Percutaneous Electrical Nerve Stimulation Versus Dry Needling: Effectiveness in the Treatment of Chronic Low Back Pain

Pressure Pain Threshold Protocols With Pressure Algometer in Patients With Low Back Pain: A Systematic Review With Meta-Analysis

OBJECTIVE

The pressure pain threshold is commonly employed to assess pain in various conditions. Despite its widespread use, the measurement of pressure pain thresholds is not consistently described across studies. Therefore, this review aimed to systematically examine the evidence regarding the assessment of pressure pain thresholds in patients with low back pain, including the protocols and body sites employed.

METHODS

Six databases were systematically screened from their earliest records to May 2023 to identify studies utilizing pressure pain thresholds. Eligibility screening was conducted for the identified studies, and the included studies underwent appraisal using the appropriate tool corresponding to their study design.

RESULTS

Upon categorizing based on the type of pain, we included 5 studies involving acute low back pain and 43 studies with chronic pain. The meta-analysis was conducted to compare subjects with and without pain, revealing no significant difference for the paraspinal region (SMD = -4.19, 95%CI = -11.7 to 3.32, z = -1.09, p = .27), piriformis (SMD = -1.24, 95%CI = -4.25 to 1.76, z = -0.81, p = .42) and quadratus lumborum musculature (SMD = -0.37, 95%CI = -1.35 to 0.60, z = -0.75, p = .45).

CONCLUSION

The paraspinal and gluteal musculature are the most frequently evaluated. Concerning the protocols for assessment, no consensus was identified. However, studies that assessed chronic low back pain typically adhered to a similar approach regarding the number of measures and a constant increase in pressure.

Systematic Review and Meta-analysis of Stimulation of the Medial Branch of the Lumbar Dorsal Rami for the Treatment of Chronic Low Back Pain

INTRODUCTION

Chronic low back pain (CLBP) is often associated with impaired motor control and degeneration of the lumbar multifidus muscles. Several studies have reported on the utility of multifidus or medial branch stimulation as a treatment. We present a systematic review and meta-analysis of studies reporting on the change in low back pain intensity with multifidus stimulation.

MATERIALS AND METHODS

A comprehensive literature search was conducted from 2010 to 2022 for randomized controlled trials or prospective reports in adults with CLBP, treated with multifidus or medial nerve stimulation through implanted or percutaneous device. Mean change (standard error) in pain intensity was extracted and data synthesized using a mixed effects regression with a random intercept for the study to account for repeated time points.

RESULTS

A total of 419 participants were enrolled in six studies; there were 25 effects (one to six time points per study), with follow-ups ranging from 1.5 to 48 months. The weighted pooled mean effect was a reduction in pain intensity (0-10 scale) of 2.9 units (95% CI: 2.1-3.7). The 95% prediction interval was a reduction in pain intensity of 0.6 to 5.2 units. The estimated probability of a reduction in pain of >two units in a new similar study is 0.84 (0.68-0.98). Meta-regression revealed that a longer follow-up time was associated with greater reductions in pain (0.25 units [0.16-0.34] per six months).

CONCLUSIONS

Medial branch stimulation for the treatment of CLBP shows a high probability of a clinically significant change in pain intensity. Longer duration of stimulation was associated with decreased low back pain intensities.

Temporal summation does not predict the acupuncture response in patients with chronic non-specific low back pain

Introduction

Previously, we had observed that immediate pain reduction after one acupuncture treatment was associated with high temporal summation of pain (TS) at a pain free control site and younger age in a mixed population of chronic pain patients. The aim of the present study was to verify these results in chronic non-specific low back pain (LBP) and to collect pilot data on the association between TS and the response to an acupuncture series.

Methods

TS at a pain free control site (back of dominant hand) and at the pain site was quantified by the pin-prick induced wind-up ratio (WUR) in 60 LBP patients aged 50 years or younger. Response to one acupuncture treatment was assessed by change in pain intensity and pressure pain threshold (PPT) at the pain site. The primary hypothesis was that a high TS (WUR > 2.5) would be associated with a clinically relevant reduction in pain intensity of at least 30%. In study part two, 26 patients received nine additional treatments. Response to the acupuncture series was assessed by the pain intensity during the last week, the PPT and the Hannover functional ability questionnaire (FFbH-R).

Results

An immediate reduction in pain intensity of at least 30% was frequent irrespective of TS at the control site (low vs. high TS 58% vs. 72%, p = 0.266). High TS at the pain site was also not significantly associated with a clinically relevant immediate reduction in pain intensity (low vs. high TS 46% vs. 73%, p = 0.064). The PPT was not changed after one acupuncture treatment. Study part two did not reveal a consistent association between TS at the control site and any of the outcome measures but also a trend toward a higher chance for a clinically relevant response along with low TS at the pain site.

Conclusion

Our results do not suggest an important role of TS for predicting a clinically important acupuncture effect or the response to a series of 10 acupuncture treatments in patients with chronic non-specific LBP. Overall high response rates imply that acupuncture is a suitable treatment option for LBP patients irrespective of their TS.

Clinical efficacy of acupuncture therapy combined with core muscle exercises in treating patients with chronic nonspecific low back pain: a systematic review and meta-analysis of randomized controlled trials

Introduction

This meta-analysis aimed to determine the clinical efficacy of acupuncture combined with core muscle exercises on pain and functional status in patients with chronic nonspecific low back pain.

Methods

This study followed the Preferred Reporting Items for Systematic Reviews and meta-analysis criteria for systematic reviews and meta-analyses. Randomized controlled trials published till November 2023 were searched in PubMed, Web of Science, Cochrane, Embase, China National Knowledge Infrastructure, Chinese Biomedical Literature, and Wanfang databases. The search strategy was related to disease type, intervention, and control measures and was structured around the search terms "low back pain," "acupuncture therapy," and "exercise." Two reviewers applied inclusion and exclusion criteria. Sensitivity and fixed effects analyses were performed to determine the primary outcomes.

Results

We included 11 randomized controlled trials (n = 727) on acupuncture combined with core muscle exercises in patients with chronic nonspecific low back pain. Compared with controls, clinical efficacy was significant, with improvements in pain scores (visual analog pain scale and numerical rating scale) and Oswestry Disability Index in the intervention group.

Discussion

Acupuncture therapy combined with core muscle exercises improved pain and functional status in patients with chronic nonspecific low back pain, with favorable clinical outcomes compared with single-core muscle training. Multicenter large-sample trials are required to obtain more reliable conclusions.

Immediate effects of percutaneous electrical nerve stimulation in patients with lateral elbow pain

INTRODUCTION

Ultrasound guided-percutaneous electrical nerve stimulation appears to be effective in the treatment of chronic musculoskeletal pain.

OBJECTIVE

To investigate the immediate effects of one session of percutaneous electrical nerve stimulation on the radial nerve in patients with lateral elbow pain.

METHODS

A randomized clinical trial was conducted. Sixty patients with chronic lateral elbow pain were allocated into real-percutaneous electrical nerve stimulation (n = 30) or sham-percutaneous electrical nerve stimulation (n = 30) where the patients received one-single session of the real or sham percutaneous stimulation on the radial nerve, respectively. Pressure pain thresholds, pain intensity, pain-free grip strength, and the self-perceived improvement were evaluated after the intervention.

RESULTS

Significant differences between groups for pain intensity (-11.55, 95% CI -21.79 to -1.30, p < .028), but not for pressure pain threshold or pain-free grip strength, were found. Patients receiving real-percutaneous stimulation had significant improvement in pain-free grip strength on the treated side. The proportion of individuals reporting moderate to large self-perceived improvement (≥4) was significantly higher (p = .026) after real-percutaneous stimulation than after sham-percutaneous stimulation.

CONCLUSION

A single session of real-percutaneous electrical nerve stimulation targeting the radial nerve in subjects with lateral elbow pain decreased pain intensity between groups and increased pain-free grip strength on the treated side but not between groups.

A Systematic Appraisal of Conflicts of Interest and Researcher Allegiance in Clinical Studies of Dry Needling for Musculoskeletal Pain Disorders

OBJECTIVE

The purpose of this study was to determine the frequency and methods of conflicts of interest (COI) reporting in published dry needling (DN) studies and to determine the frequency of researcher allegiance (RA).

METHODS

A pragmatic systematic search was undertaken to identify DN studies that were included in systematic reviews. Information regarding COI and RA were extracted from the full text of the published DN reports, and study authors were sent a survey inquiring about the presence of RA. A secondary analysis also was undertaken based on study quality/risk of bias scores that were extracted from the corresponding systematic reviews and study funding extracted from each DN study.

RESULTS

Sixteen systematic reviews were identified, containing 60 studies of DN for musculoskeletal pain disorders, 58 of which were randomized controlled trials. Of the DN studies, 53% had a COI statement. None of these studies disclosed a COI. Nineteen (32%) authors of DN studies responded to the survey. According to the RA survey, 100% of DN studies included at least 1 RA criterion. According to the data extraction, 1 RA criterion was met in 45% of the DN studies. The magnitude of RA per study was 7 times higher according to the surveys than in the published reports.

CONCLUSION

These results suggest that COI and RA might be underreported in studies of DN. In addition, authors of DN studies might be unaware of the potential influence of RA on study results and conclusions.

IMPACT

Improved reporting of COI/RA might improve credibility of results and help identify the various factors involved in complex interventions provided by physical therapists. Doing so could help optimize treatments for musculoskeletal pain disorders provided by physical therapists.

Duration of Electro-Dry Needling Does Not Change the Pain Response After Repeated Nociceptive Thermal Stimuli in Asymptomatic Individuals: A Randomized Intervention Study

Objective

To assess the effects of 5 different durations of electro-dry needling (EDN) on asymptomatic individuals' pain response after repeated noxious thermal stimuli.

Design

Randomized, non-controlled intervention trial.

Setting

University laboratory.

Participants

Asymptomatic participants (N=50) were recruited for the study and randomized into 5 groups. There were 33 women with an average age of 26.8 (±4.8) years. To participate in the study, individuals had to be between the ages of 18 and 40, free of any musculoskeletal injury which prevented participation of daily activities, and not pregnant or trying to become pregnant.

Interventions

Participants were randomly assigned to receive 5 different durations of EDN: 10, 15, 20, 25, and 30 minutes. To perform the EDN, 2 monofilament needles were inserted lateral to the lumbar spinous processes of L3 and L5 on the right. Needles were left in situ with electrical stimulation at a frequency of 2 Hz and an amplitude which resulted in a 3 to 6 out of 10 intensity pain rating by the participant.

Main Outcome Measures

The change in the magnitude of pain in response to repetitive heat-pulses before and after the EDN procedure.

Results

There was a significant reduction in the magnitude of pain in response across the groups after EDN (F(1,42)=94.12, P<.001, ƞp2=.691). However, the interaction between time and group was not significant (F(4,42)=1.019, P=.409, ƞp2=.088), indicating that no duration of EDN was superior to another in reducing temporal summation.

Conclusions

This study suggests that in asymptomatic individuals, performing EDN beyond 10 minutes does not provide any additional benefits in the reduction of the magnitude of pain in response to thermal nociceptive stimuli. Additional study in symptomatic populations is required for generalizability in clinical settings.

Effects of percutaneous neuromodulation in neuromusculoskeletal pathologies: A systematic review

BACKGROUND

Percutaneous neuromodulation (PNM) consists in using electrical stimulation on a peripheral nerve by using a needle as an electrode in order to lessen the pain and restore both neuromuscular and nervous system functions. The aims of the present study were to evaluate the current scientific evidence of the effects of PNM on pain and physical capabilities in neuromusculoskeletal injuries.

METHODS

Data sources: There was used the PRISMA protocol. In order to do the literature research, there were used the PubMed, Cochrane, Scopus, and Web of Science databases. Study selection or eligibility criteria: There were also included experimental clinical trials published between 2010 and nowadays, tested on humans, which feature treatment based on needles with electrical stimulation in order to treat neuromusculoskeletal injuries. Study appraisal and synthesis methods: A quality assessment was performed according to the PEDro scale and reviewed the impact factor and quartile of the journal.

RESULTS

The treatment resulted in significant improvement in terms of pain intensity, pressure pain threshold, balance, muscular endurance, functionality/disability, subjective improvement, function of the descending pain modulatory system, and intake of drugs. Limitations: the lack of previous research studies on the subject and the lack of data on opioid intake in the selected studies.

CONCLUSION

Treatment based on PNM may be an alternative when treating injuries in soft tissues without significant side effects. However, there are few articles investigating the effects of PNM so more evidence is needed to draw solid conclusions.

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.

Is Dry Needling Applied by Physical Therapists Effective for Pain in Musculoskeletal Conditions? A Systematic Review and Meta-Analysis

OBJECTIVE

The main objective of this systematic review and meta-analysis was to determine the short-, medium-, and long-term effectiveness of dry needling (DN) applied by physical therapists to myofascial trigger points for the treatment of pain.

METHODS

PubMed, Scopus, SportDiscus, and Web of Science databases were searched from their inception to February 2020. Randomized controlled trials that compared DN with other treatments or placebo and measured pain with a visual analog Scale or another numerical pain rating scale were included. Two authors used a personalized form to collect the following data relevant to the objectives of the review from each article independently: study design, purpose, sample size, diagnosis, characteristics of DN intervention, characteristics of placebo intervention, outcome measures, period of assessment, body region, DN technique, and number of sessions. The initial search identified 1771 articles. After the selection, 102 articles were assessed for eligibility; 42 of these articles measuring pain were used for the meta-analysis. Four meta-analyses were performed according to the follow-up period from the last reported treatment.

RESULTS

This meta-analysis found a large effect to decrease pain within 72 hours (standardized mean difference [SMD] = -0.81; 95% CI = -1.21 to -0.40), a moderate effect in 1 to 3 weeks (SMD = -0.69; 95% CI = -1.02 to -0.35), a large effect in 4 to 12 weeks (SMD = -0.85; 95% CI = -1.30 to -0.40), and a large effect in 13 to 24 weeks (SMD = -0.81; 95% CI = -1.64 to -0.03). The risk of bias was generally low; however, the heterogeneity of the results downgraded the level of evidence.

CONCLUSIONS

Low-quality evidence that the immediate to 72-hour (large) effect, 4- to 12-week (large) effect, 13- to 24-week (large) effect, and moderate-quality 1- to 3-week (moderate) effect suggested that DN performed by physical therapists was more effective than no treatment, sham DN, and other therapies for reducing pain.

IMPACT

DN is commonly used by physical therapists to treat musculoskeletal pain, and it is very important for physical therapists to know the clinical conditions and time periods for which DN is effective in reducing pain in their patients.

Acupuncture for chronic nonspecific low back pain

BACKGROUND

Chronic nonspecific low back pain (LBP) is very common; it is defined as pain without a recognizable etiology that lasts for more than three months. Some clinical practice guidelines suggest that acupuncture can offer an effective alternative therapy. This review is a split from an earlier Cochrane review and it focuses on chronic LBP.

OBJECTIVES

To assess the effects of acupuncture compared to sham intervention, no treatment, or usual care for chronic nonspecific LBP.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, two Chinese databases, and two trial registers to 29 August 2019 without restrictions on language or publication status. We also screened reference lists and LBP guidelines to identify potentially relevant studies.

SELECTION CRITERIA

We included only randomized controlled trials (RCTs) of acupuncture for chronic nonspecific LBP in adults. We excluded RCTs that investigated LBP with a specific etiology. We included trials comparing acupuncture with sham intervention, no treatment, and usual care. The primary outcomes were pain, back-specific functional status, and quality of life; the secondary outcomes were pain-related disability, global assessment, or adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the studies, assessed the risk of bias and extracted the data. We meta-analyzed data that were clinically homogeneous using a random-effects model in Review Manager 5.3. Otherwise, we reported the data qualitatively. We used the GRADE approach to assess the certainty of the evidence.

MAIN RESULTS

We included 33 studies (37 articles) with 8270 participants. The majority of studies were carried out in Europe, Asia, North and South America. Seven studies (5572 participants) conducted in Germany accounted for 67% of the participants. Sixteen trials compared acupuncture with sham intervention, usual care, or no treatment. Most studies had high risk of performance bias due to lack of blinding of the acupuncturist. A few studies were found to have high risk of detection, attrition, reporting or selection bias. We found low-certainty evidence (seven trials, 1403 participants) that acupuncture may relieve pain in the immediate term (up to seven days) compared to sham intervention (mean difference (MD) -9.22, 95% confidence interval (CI) -13.82 to -4.61, visual analogue scale (VAS) 0-100). The difference did not meet the clinically important threshold of 15 points or 30% relative change. Very low-certainty evidence from five trials (1481 participants) showed that acupuncture was not more effective than sham in improving back-specific function in the immediate term (standardized mean difference (SMD) -0.16, 95% CI -0.38 to 0.06; corresponding to the Hannover Function Ability Questionnaire (HFAQ, 0 to 100, higher values better) change (MD 3.33 points; 95% CI -1.25 to 7.90)). Three trials (1068 participants) yielded low-certainty evidence that acupuncture seemed not to be more effective clinically in the short term for quality of life (SMD 0.24, 95% CI 0.03 to 0.45; corresponding to the physical 12-item Short Form Health Survey (SF-12, 0-100, higher values better) change (MD 2.33 points; 95% CI 0.29 to 4.37)). The reasons for downgrading the certainty of the evidence to either low to very low were risk of bias, inconsistency, and imprecision. We found moderate-certainty evidence that acupuncture produced greater and clinically important pain relief (MD -20.32, 95% CI -24.50 to -16.14; four trials, 366 participants; (VAS, 0 to 100), and improved back function (SMD -0.53, 95% CI -0.73 to -0.34; five trials, 2960 participants; corresponding to the HFAQ change (MD 11.50 points; 95% CI 7.38 to 15.84)) in the immediate term compared to no treatment. The evidence was downgraded to moderate certainty due to risk of bias. No studies reported on quality of life in the short term or adverse events. Low-certainty evidence (five trials, 1054 participants) suggested that acupuncture may reduce pain (MD -10.26, 95% CI -17.11 to -3.40; not clinically important on 0 to 100 VAS), and improve back-specific function immediately after treatment (SMD: -0.47; 95% CI: -0.77 to -0.17; five trials, 1381 participants; corresponding to the HFAQ change (MD 9.78 points, 95% CI 3.54 to 16.02)) compared to usual care. Moderate-certainty evidence from one trial (731 participants) found that acupuncture was more effective in improving physical quality of life (MD 4.20, 95% CI 2.82 to 5.58) but not mental quality of life in the short term (MD 1.90, 95% CI 0.25 to 3.55). The certainty of evidence was downgraded to moderate to low because of risk of bias, inconsistency, and imprecision. Low-certainty evidence suggested a similar incidence of adverse events immediately after treatment in the acupuncture and sham intervention groups (four trials, 465 participants) (RR 0.68 95% CI 0.46 to 1.01), and the acupuncture and usual care groups (one trial, 74 participants) (RR 3.34, 95% CI 0.36 to 30.68). The certainty of the evidence was downgraded due to risk of bias and imprecision. No trial reported adverse events for acupuncture when compared to no treatment. The most commonly reported adverse events in the acupuncture groups were insertion point pain, bruising, hematoma, bleeding, worsening of LBP, and pain other than LBP (pain in leg and shoulder).

AUTHORS' CONCLUSIONS

We found that acupuncture may not play a more clinically meaningful role than sham in relieving pain immediately after treatment or in improving quality of life in the short term, and acupuncture possibly did not improve back function compared to sham in the immediate term. However, acupuncture was more effective than no treatment in improving pain and function in the immediate term. Trials with usual care as the control showed acupuncture may not reduce pain clinically, but the therapy may improve function immediately after sessions as well as physical but not mental quality of life in the short term. The evidence was downgraded to moderate to very low-certainty considering most of studies had high risk of bias, inconsistency, and small sample size introducing imprecision. The decision to use acupuncture to treat chronic low back pain might depend on the availability, cost and patient's preferences.

Dry needling strategies for musculoskeletal conditions: Do the number of needles and needle retention time matter? A narrative literature review

Acupuncture and dry needling are both minimally invasive procedures that use thin, filiform needles without injectate for the management of a variety of neuromusculoskeletal pain conditions. While the theoretical constructs underlying the use of acupuncture and dry needling are unique, both appear to have the ability to elicit biochemical, biomechanical, endocrinological and neurovascular changes associated with reductions in pain and disability. However, optimal treatment dosage has yet to be determined, and there is a lack of consistency in the literature on the number of needles that should be inserted and the needle retention time. Therefore, the purpose of this narrative review is to further explore the importance of these two variables. While trigger point dry needling advocates single needle insertions via repetitive, quick in-and-out pistoning, most acupuncture and dry needling clinical trials have incorporated multiple needles for five to 40 min. Notably and to date, using a single needle to repeatedly prick trigger points one at a time with fast-in and fast-out pistoning maneuvers has not yet been shown to produce significant and clinically meaningful long term improvements in pain and disability in a wide array of musculoskeletal conditions. Insertion of multiple needles for typically 20-30 min durations has been shown to produce larger treatment effect sizes and longer-lasting outcomes than brief, single-needle strategies. Moreover, the number of needles and needle retention time are two variables associated with treatment dosage and must be carefully matched with specific musculoskeletal conditions and the patient's goals.

Criteria Used for the Diagnosis of Myofascial Trigger Points in Clinical Trials on Physical Therapy: Updated Systematic Review

OBJECTIVE

The objective of this study was to conduct an updated systematic review of diagnostic criteria for myofascial trigger points (MTrPs) used in clinical trials of physical therapy interventions from 2007 to 2019.

METHODS

MEDLINE and Physiotherapy Evidence Database (PEDro) were searched using the following MeSH keywords: "trigger points," "trigger point," "myofascial trigger point," "myofascial trigger points," "myofascial pain," and "myofascial pain syndrome." The MeSH keywords were combined by using Boolean operators "OR"/"AND." All physiotherapy clinical trials including patients with musculoskeletal conditions characterized by at least 1 active MTrP or latent MTrP in any body area were selected. We pooled data from an individual criterion and criteria combinations used to diagnose MTrPs. The protocol was developed in accordance with the PRISMA-P guidelines.

RESULTS

Of 478 possibly relevant publications, 198 met the inclusion criteria. Of these 198 studies, 129 studies (65.1%) stated specifically the diagnostic criteria used for MTrPs in the main text, 56 studies (28.3%) failed to report any method whereby MTrP was diagnosed, and 13 studies (6.6%) adopted expert-based definitions for MTrPs without specification. Of 129 studies, the 6 criteria applied most commonly were: "spot tenderness" (n=125, 96.9%), "referred pain" (95, 73.6%), "local twitch response" (63, 48.8%), pain recognition (59, 45.7%), limited range of motion" (29, 22.5%), and "jump sign" (10, 7.8%). Twenty-three combinations of diagnostic criteria were identified. The most frequently used combination was "spot tenderness," "referred pain," and "local twitch response" (n=28 studies, 22%).

CONCLUSIONS

A number of the included studies failed in properly reporting the MTrP diagnostic criteria. Moreover, high variability in the use of MTrP diagnostic was also observed. Spot tenderness, referred pain, and local twitch response were the 3 most popular criteria (and the most frequently used combination). A lack of transparency in the reporting of MTrP diagnostic criteria is present in the literature.

REGISTRY

This systematic review was registered under the Centre for Reviews and Dissemination, PROSPERO number: CRD42018087420.

Day of peak pain reduction by a single session of dry needling in the upper trapezius myofascial trigger points: A 14 daily follow-up study

BACKGROUND

Dry needling (DN) is commonly used to inactivate myofascial trigger points (MTrPs). However, a daily report of pain reduction has not been determined.

OBJECTIVE

The aim was to evaluate the time of the greatest pain relief after performing a single session of DN in MTrPs of the upper trapezius muscle.

METHODS

A patient who had MTrPs in the upper trapezius muscle was enrolled into a prospective descriptive study. Each patient received a single session of DN, using a fast-in-fast-out technique, with needle retention for 30 min. Numerical rating scale (NRS) scores were collected daily for 14 days. The mean difference of pain and an effect size were calculated. The 1-5 satisfaction score was a secondary outcome.

RESULTS

Sixty-seven subjects completed the intervention. The mean duration of the symptom was 27.32 months. The mean baseline NRS score was 5.30. The pain decreased significantly between immediate post-procedure and 1 day after the DN treatment from 5.16 to 3.40 (mean difference 1.76, p < 0.01, effect size = 0.87). The pain continuously reduced until day 10 and then it gradually rose. The pain on day 10 was compared with the baseline that revealed the largest effect size of 3.08 (mean difference 4.67, p < 0.01). Eighty-eight percent of the subjects were very satisfied with their treatment.

CONCLUSIONS

A single session of DN treatment in the upper trapezius MTrPs combined with self-stretching exercises could greatly reduce pain between immediate post-procedure and 1 day after DN treatment. The peak effect on pain reduction occurred on day 10.

Dry needling for spine related disorders: a scoping review

Introduction/Background

The depth and breadth of research on dry needling (DN) has not been evaluated specifically for symptomatic spine related disorders (SRD) from myofascial trigger points (TrP), disc, nerve and articular structures not due to serious pathologies. Current literature appears to support DN for treatment of TrP. Goals of this review include identifying research published on DN treatment for SRD, sites of treatment and outcomes studied.

Methods

A scoping review was conducted following Levac et al.’s five part methodological framework to determine the current state of the literature regarding DN for patients with SRD.

Results

Initial and secondary search strategies yielded 55 studies in the cervical (C) region (71.43%) and 22 in the thoracolumbar-pelvic (TLP) region (28.57%). Most were randomized controlled trials (60% in C, 45.45% in TLP) and clinical trials (18.18% in C, 22.78% in TLP). The most commonly treated condition was TrP for both the C and TLP regions. In the C region, DN was provided to 23 different muscles, with the trapezius as treatment site in 41.88% of studies. DN was applied to 31 different structures in the TLP region. In the C region, there was one treatment session in 23 studies (41.82%) and 2–6 treatments in 25 (45.45%%). For the TLP region, one DN treatment was provided in 8 of the 22 total studies (36.36%) and 2–6 in 9 (40.9%). The majority of experimental designs had DN as the sole intervention. For both C and TLP regions, visual analogue scale, pressure pain threshold and range of motion were the most common outcomes.

Conclusion

For SRD, DN was primarily applied to myofascial structures for pain or TrP diagnoses. Many outcomes were improved regardless of diagnosis or treatment parameters. Most studies applied just one treatment which may not reflect common clinical practice. Further research is warranted to determine optimal treatment duration and frequency. Most studies looked at DN as the sole intervention. It is unclear whether DN alone or in addition to other treatment procedures would provide superior outcomes. Functional outcome tools best suited to tracking the outcomes of DN for SRD should be explored.

Effectiveness of percutaneous electrical nerve stimulation for musculoskeletal pain: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

To evaluate the effects of percutaneous electrical stimulation (PENS) alone or as an adjunct with other interventions on pain and related disability in musculoskeletal pain conditions.

DATABASES AND DATA TREATMENT

Search of MEDLINE, EMBASE, AMED, CINAHL, EBSCO, PubMed, PEDro, Cochrane Library, SCOPUS and Web of Science databases. Randomized controlled trials where at least one group received any form of PENS for musculoskeletal condition. Studies had to include humans and collect outcomes on pain and related disability in musculoskeletal pain. Risk of bias was assessed by the Cochrane Guidelines, the quality of evidence by using the GRADE approach. Standardized mean differences (SMD) were calculated.

RESULTS

Sixteen studies were included and included heterogeneous musculoskeletal conditions with short- or midterm follow-ups. PENS alone had a large effect (SMD -1.22, 95% CI -1.66 to -0.79) on pain and a small effect (SMD -0.33, 95% CI -0.61 to -0.06) on related disability at short-term as compared with sham. A moderate effect of PENS alone (SMD -0.71, 95% CI -1.23 to -0.19) on pain when compared with other interventions was observed. The inclusion of PENS with other interventions had a moderate effect for decreasing pain at short- (SMD -0.70, 95% CI -1.02 to -0.37) and midterm (SMD -0.68, 95% CI -1.10 to -0.27). No effect at midterm (SMD -0.21, 95% CI -0.52 to 0.10) on related disability was seen. The risk of bias was generally low; but the heterogenicity of the results downgraded the level of evidence.

CONCLUSION

There is low level of evidence suggesting the effects of PENS alone or in combination for pain, but not related disability, in musculoskeletal pain.

LEVEL OF EVIDENCE

Therapy, level 1a. Registration number: CRD42019131331.

SIGNIFICANCE

This meta-analysis investigating the effectiveness of PENS for the management of pain and related disability in musculoskeletal pain conditions found that PENS could decrease level of pain intensity but not relateddisability in musculoskeletal pain disorders.

The Effect of Electric Stimulation Techniques on Pain and Tenderness at the Myofascial Trigger Point: A Systematic Review

BACKGROUND

Myofascial pain is a prevalent chronic pain disorder, affecting a large proportion of the general population. Electric stimulation techniques such as transcutaneous electric stimulation (TENS) and electroacupuncture have been shown to be effective for managing chronic pain conditions including myofascial pain. The goal of this study was to review the literature on the effectiveness of electric stimulation techniques on myofascial pain.

METHODS

A comprehensive systematic search of three databases-Medline, EMBASE, and Cochrane CENTRAL-was conducted using key words related to myofascial pain and trigger points, as well as various electric stimulation techniques. A total of 15 articles passed the inclusion and exclusion criteria for the study. Data were extracted from these studies and assessed qualitatively and quantitatively. Standardized mean differences (SMDs) were computed from pain intensity measures extracted from these studies. Subgroup analyses were performed to assess the effectiveness of treatment modality, number of treatment sessions, frequency of stimulation, location of treatment, and duration of treatment.

RESULTS

The SMD for electric stimulation techniques on reported pain intensity was significant (P = 0.03), as was the SMD for the electroacupuncture subgroup (P = 0.02); the TENS subgroups' effect was not significant (P = 0.17). The subgroup analyses tentatively suggest that frequency and number of treatments do not influence pain intensity, whereas the duration of treatment may have an effect. The qualitative results of this study revealed variability in the results among studies delivering TENS treatments.

CONCLUSIONS

Electric stimulation is effective at mitigating reported pain intensity at the location of the trigger point. Electroacupuncture presented with significant and larger effect sizes of improvement relative to TENS for reported pain intensity. Given that this review included a small number of studies, there is a need for additional research to confirm its findings. Additionally, studies assessing the parameters and physiological location of treatment are needed to inform the clinical use and recommendations of electric stimulation treatments.

A critical overview of the current myofascial pain literature - February 2019

This edition of the overview of current myofascial pain literature features several interesting and important publications. From Australia, Braithwaite and colleagues completed an outstanding systematic review of blinding procedures used in dry needling (DN) studies. Other papers tackled the interrater reliability of the identification of trigger points (TrP), the presence of muscle hardness related to latent TrPs, pelvic floor examination techniques, and the links between TrPs, headaches and shoulder pain. Israeli researchers developed a theoretical model challenging the contributions of the Cinderella Hypothesis to the development of TrPs. As in almost all issues, we included many DN, injection and acupuncture studies, which continue to be the focus of researchers all over the world.

Postneedling Soreness and Tenderness After Different Dosages of Dry Needling of an Active Myofascial Trigger Point in Patients With Neck Pain: A Randomized Controlled Trial

BACKGROUND

Previous studies in asymptomatic subjects have demonstrated that myofascial trigger point (MTrP) dry needling frequently is associated with postneedling soreness. However, to the authors' knowledge, there is not any study that performs a detailed description of postneedling soreness characteristics in patients with myofascial pain. This information could help clinicians to make evidence-informed decisions considering the benefits and negative effects of different dry needling dosages.

OBJECTIVE

To (1) compare the prevalence, intensity, and duration of postneedling soreness and tenderness after different dosages of deep dry needling (DDN) and (2) analyze the influence on postneedling soreness of psychological factors and other factors involved in the DDN process DESIGN: 1-week follow-up, double-blind randomized controlled trial.

SETTING

University community.

PARTICIPANTS

Patients (n = 120: 34 male; 86 female) aged 18-53 years (median ± interquartile range, 21.0 ± 7.0 years) with active MTrPs in the upper trapezius.

INTERVENTION

All patients received DDN in an active MTrP. They were randomly divided into 4 groups: no local twitch responses (LTRs) elicited (control group), 4 LTRs elicited, 6 LTRs elicited, and DDN until no more LTRs were elicited.

MAIN OUTCOME MEASURES

Postneedling soreness and pressure pain threshold were assessed before treatment, during DDN procedure, and every 24 hours during 1 week.

RESULTS

Postneedling soreness showed a significant effect for time (F_2,006 = 173.603; P < .001, η_p² = 0.659) and a significant interaction between group and time (F_6,017 = 3.763; P = .001; η_p² = 0.111). Pressure pain threshold showed a significant effect for time (F_2,377 = 16.833; P < .001; η_p² = 0.127) and a significant interaction between group and time (F_7,130 = 2.100; P = .04; η_p² = 0.052). Psychological factors did not show relevant correlations with the intensity of postneedling soreness.

CONCLUSIONS

Postneedling soreness is present in most of subjects after DDN of active MTrPs. The groups in which DDN was performed eliciting LTRs exhibited greater post-needling soreness. The number of needle insertions was associated with postneedling soreness but psychological factors did not seem to play a relevant role on its perception.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02190890 LEVEL OF EVIDENCE: I.

Post-needling soreness after myofascial trigger point dry needling: Current status and future research

Post-dry needling soreness is a common complication of myofascial trigger point (MTrP) dry needling treatment. The prevention, management and relevance of this complication remain uncertain. This paper examines the current state of knowledge and suggests directions for further studies in this area. MTrPs are hypersensitive nodules in skeletal muscles' taut bands, present in several pain conditions. Dry needling has been recommended for relieving MTrP pain. MTrP dry needling procedures have shown to be associated with post-needling soreness, which is thought to be a consequence of the neuromuscular damage, and hemorrhagic and inflammatory reaction generated by the needle. Postneedling soreness is a very frequent effect after deep dry needling, usually lasting less than 72 h. It may not be especially distressing for most patients. However, patients presenting with higher levels of post-needling soreness, not perceiving dry needling effectiveness in the first session, or not having high myofascial pain intensity before treatment, could be the most likely to find post-needling soreness more distressing, functionally limiting and to abandon treatment. Future research should assess the clinical relevance of post-needling soreness. Post-needling soreness should be considered when investigating dry needling effectiveness since it could overlie the original myofascial pain and influence the patients' pain ratings.

Dry Needling for Patients With Neck Pain: Protocol of a Randomized Clinical Trial

BACKGROUND

Neck pain is a costly and common problem. Current treatments are not adequately effective for a large proportion of patients who continue to experience recurrent pain. Therefore, new treatment strategies should be investigated in an attempt to reduce the disability and high costs associated with neck pain. Dry needling is a technique in which a fine needle is used to penetrate the skin, subcutaneous tissues, and muscle with the intent to mechanically disrupt tissue without the use of an anesthetic. Dry needling is emerging as a treatment modality that is widely used clinically to address a variety of musculoskeletal conditions. Recent studies of dry needling in mechanical neck pain suggest potential benefits, but do not utilize methods typical to clinical practice and lack long-term follow-up. Therefore, a clinical trial with realistic treatment time frames and methods consistent with clinical practice is needed to examine the effectiveness of dry needling on reducing pain and enhancing function in patients presenting to physical therapy with mechanical neck pain.

OBJECTIVE

The aim of this trial will be to examine the short- and long-term effectiveness of dry needling delivered by a physical therapist on pain, disability, and patient-perceived improvements in patients with mechanical neck pain.

METHODS

We will conduct a randomized, double-blind, placebo-controlled trial in accordance with the CONSORT guidelines. A total of 76 patients over the age of 18 with acute or chronic mechanical neck pain resulting from postural dysfunction, trauma, or insidious onset who are referred to physical therapy will be enrolled after meeting the eligibility criteria. Subjects will be excluded if they have previous history of surgery, whiplash in the last 6 weeks, nerve root compression, red flags, or contraindications to dry needling or manual therapy. Participants will be randomized to receive (1) dry needling, manual therapy, and exercise or (2) sham dry needling, manual therapy, and exercise. Participants will receive seven physical therapy treatments lasting 45 minutes each over a maximum of 4 weeks. The primary outcome will be disability as measured by the Neck Disability Index. Secondary outcomes include the following: pain, patient-perceived improvement, patient expectations, and successful blinding to the needling intervention. Outcome measures will be assessed at 4 weeks, 6 months, and 12 months by an assessor who is blind to the group allocation of the participants to determine the short- and long-term treatment effects. We will examine the primary aim with a two-way, repeated-measures analysis of variance with treatment group as the between-subjects variable and time as the within-subjects variable. The hypothesis of interest will be the two-way group by time interaction. An a priori alpha level of .05 will be used for all analyses.

RESULTS

Recruitment is currently underway and is expected to be completed by the end of 2017. Data collection for long-term outcomes will occur throughout 2017 and 2018. Data analysis, preparation, and publication submission is expected to occur throughout the final three quarters of 2018.

CONCLUSIONS

The successful completion of this trial will provide evidence to demonstrate whether dry needling is effective for the management of mechanical neck pain when used in a combined treatment approach, as is the common clinical practice.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02731014; https://clinicaltrials.gov/ct2/show/NCT02731014 (Archived by WebCite at http://www.webcitation.org/6ujZgbhsq).

The Effectiveness of Trigger Point Dry Needling for Musculoskeletal Conditions by Physical Therapists: A Systematic Review and Meta-analysis

Study Design Systematic review and meta-analysis. Background An increasing number of physical therapists in the United States and throughout the world are using dry needling to treat musculoskeletal pain. Objective To examine the short- and long-term effectiveness of dry needling delivered by a physical therapist for any musculoskeletal pain condition. Methods Electronic databases were searched. Eligible randomized controlled trials included those with human subjects who had musculoskeletal conditions that were treated with dry needling performed by a physical therapist, compared with a control or other intervention. The overall quality of the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation. Results The initial search returned 218 articles. After screening, 13 were included. Physiotherapy Evidence Database quality scale scores ranged from 4 to 9 (out of a maximum score of 10), with a median score of 7. Eight meta-analyses were performed. In the immediate to 12-week follow-up period, studies provided evidence that dry needling may decrease pain and increase pressure pain threshold when compared to control/sham or other treatment. At 6 to 12 months, dry needling was favored for decreasing pain, but the treatment effect was not statistically significant. Dry needling, when compared to control/sham treatment, provides a statistically significant effect on functional outcomes, but not when compared to other treatments. Conclusion Very low-quality to moderate-quality evidence suggests that dry needling performed by physical therapists is more effective than no treatment, sham dry needling, and other treatments for reducing pain and improving pressure pain threshold in patients presenting with musculoskeletal pain in the immediate to 12-week follow-up period. Low-quality evidence suggests superior outcomes with dry needling for functional outcomes when compared to no treatment or sham needling. However, no difference in functional outcomes exists when compared to other physical therapy treatments. Evidence of long-term benefit of dry needling is currently lacking. Level of Evidence Therapy, level 1a. J Orthop Sports Phys Ther 2017;47(3):133-149. Epub 3 Feb 2017. doi:10.2519/jospt.2017.7096.

Contribution of Dry Needling to Individualized Physical Therapy Treatment of Shoulder Pain: A Randomized Clinical Trial

Study Design Multicenter, parallel randomized clinical trial. Background Myofascial trigger points (MTrPs) are implicated in shoulder pain and functional limitations. An intervention intended to treat MTrPs is dry needling. Objectives To investigate the effectiveness of dry needling in addition to evidence-based personalized physical therapy treatment in the treatment of shoulder pain. Methods One hundred twenty patients with nonspecific shoulder pain were randomly allocated into 2 parallel groups: (1) personalized, evidencebased physical therapy treatment; and (2) trigger point dry needling in addition to personalized, evidence-based physical therapy treatment. Patients were assessed at baseline, posttreatment, and 3-month follow-up. The primary outcome measure was pain assessed by a visual analog scale at 3 months, and secondary variables were joint range-of-motion limitations, Constant-Murley score for pain and function, and number of active MTrPs. Clinical efficacy was assessed using intention-to-treat analysis. Results Of the 120 enrolled patients, 63 were randomly assigned to the control group and 57 to the intervention group. There were no significant differences in outcome between the 2 treatment groups. Both groups showed improvement over time. Conclusion Dry needling did not offer benefits in addition to personalized, evidencebased physical therapy treatment for patients with nonspecific shoulder pain. Level of Evidence Therapy, level 1b. Registered February 11, 2009 at www.isrctn.com (ISRCTN30907460). J Orthop Sports Phys Ther 2017;47(1):11-20. Epub 9 Dec 2016. doi:10.2519/jospt.2017.6698.

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.

The effect of journal impact factor, reporting conflicts, and reporting funding sources, on standardized effect sizes in back pain trials: a systematic review and meta-regression

BACKGROUND

Low back pain is a common and costly health complaint for which there are several moderately effective treatments. In some fields there is evidence that funder and financial conflicts are associated with trial outcomes. It is not clear whether effect sizes in back pain trials relate to journal impact factor, reporting conflicts of interest, or reporting funding.

METHODS

We performed a systematic review of English-language papers reporting randomised controlled trials of treatments for non-specific low back pain, published between 2006-2012. We modelled the relationship using 5-year journal impact factor, and categories of reported of conflicts of interest, and categories of reported funding (reported none and reported some, compared to not reporting these) using meta-regression, adjusting for sample size, and publication year. We also considered whether impact factor could be predicted by the direction of outcome, or trial sample size.

RESULTS

We could abstract data to calculate effect size in 99 of 146 trials that met our inclusion criteria. Effect size is not associated with impact factor, reporting of funding source, or reporting of conflicts of interest. However, explicitly reporting 'no trial funding' is strongly associated with larger absolute values of effect size (adjusted β=1.02 (95 % CI 0.44 to 1.59), P=0.001). Impact factor increases by 0.008 (0.004 to 0.012) per unit increase in trial sample size (P<0.001), but does not differ by reported direction of the LBP trial outcome (P=0.270).

CONCLUSIONS

The absence of associations between effect size and impact factor, reporting sources of funding, and conflicts of interest reflects positively on research and publisher conduct in the field. Strong evidence of a large association between absolute magnitude of effect size and explicit reporting of 'no funding' suggests authors of unfunded trials are likely to report larger effect sizes, notwithstanding direction. This could relate in part to quality, resources, and/or how pragmatic a trial is.

The effect of the combination of dry needling and MET on latent trigger point upper trapezius in females

AIM

The purpose of this clinical trial experiment was to compare the effects of the combination of dry needling (DN) and the muscle energy technique (MET) on the upper trapezius latent myofascial trigger point.

METHOD

Sixty female patients, aged 18-30 with latent myofascial trigger points in the upper trapezius muscle were randomly divided into three groups: group 1 (n = 20) received DN and MET, group 2 (n = 20) received only MET, and group 3 (n = 20) received only DN. The visual analogue scale (VAS), pressure pain threshold (PPT), and range of active contra lateral flexion (CLF) were measured before each treatment. The patients were treated for three sessions in a one-week period with at least a two-day break between each session, and in session four, an assessment of primary outcomes was conducted without any treatment.

RESULTS

All three treatment groups showed decreases in pain (p = 0.001) and increases in PPT levels (p = 0.001) as well as increases in CLF (p = 0.001). But the group receiving trigger point DN together with MET showed more significant improvement than the other two groups in VAS, PPT and ROM. No significant differences were found between the MET-only group and the DN-only group.

CONCLUSION

Our results indicate that all three treatments used in this study were effective for treating MTP. According to this study, DN and MET is suggested as a new method for the treatment of MTP.

Effects of acupuncture on sensory perception: a systematic review and meta-analysis

BACKGROUND

The effect of acupuncture on sensory perception has never been systematically reviewed; although, studies on acupuncture mechanisms are frequently based on the idea that changes in sensory thresholds reflect its effect on the nervous system.

METHODS

Pubmed, EMBASE and Scopus were screened for studies investigating the effect of acupuncture on thermal or mechanical detection or pain thresholds in humans published in English or German. A meta-analysis of high quality studies was performed.

RESULTS

Out of 3007 identified articles 85 were included. Sixty five studies showed that acupuncture affects at least one sensory threshold. Most studies assessed the pressure pain threshold of which 80% reported an increase after acupuncture. Significant short- and long-term effects on the pressure pain threshold in pain patients were revealed by two meta-analyses including four and two high quality studies, respectively. In over 60% of studies, acupuncture reduced sensitivity to noxious thermal stimuli, but measuring methods might influence results. Few but consistent data indicate that acupuncture reduces pin-prick like pain but not mechanical detection. Results on thermal detection are heterogeneous. Sensory threshold changes were equally frequent reported after manual acupuncture as after electroacupuncture. Among 48 sham-controlled studies, 25 showed stronger effects on sensory thresholds through verum than through sham acupuncture, but in 9 studies significant threshold changes were also observed after sham acupuncture. Overall, there is a lack of high quality acupuncture studies applying comprehensive assessments of sensory perception.

CONCLUSIONS

Our findings indicate that acupuncture affects sensory perception. Results are most compelling for the pressure pain threshold, especially in pain conditions associated with tenderness. Sham acupuncture can also cause such effects. Future studies should incorporate comprehensive, standardized assessments of sensory profiles in order to fully characterize its effect on sensory perception and to explore the predictive value of sensory profiles for the effectiveness of acupuncture.

Trigger point needling: techniques and outcome

In this review we provide the updates on last years' advancements in basic science, imaging methods, efficacy, and safety of dry needling of myofascial trigger points (MTrPs). The latest studies confirmed that dry needling is an effective and safe method for the treatment of MTrPs when provided by adequately trained physicians or physical therapists. Recent basic studies have confirmed that at the site of an active MTrP there are elevated levels of inflammatory mediators, known to be associated with persistent pain states and myofascial tenderness and that this local milieu changes with the occurrence of local twitch response. Two new modalities, sonoelastography and magnetic resonance elastography, were recently introduced allowing noninvasive imaging of MTrPs. MTrP dry needling, at least partially, involves supraspinal pain control via midbrain periaqueductal gray matter activation. A recent study demonstrated that distal muscle needling reduces proximal pain by means of the diffuse noxious inhibitory control. Therefore, in a patient too sensitive to be needled in the area of the primary pain source, the treatment can be initiated with distal needling.

Relationship between quantitative sensory testing and pain or disability in people with spinal pain-a systematic review and meta-analysis

Sensitization of the nervous system can present as pain hypersensitivity that may contribute to clinical pain. In spinal pain, however, the relationship between sensory hypersensitivity and clinical pain remains unclear. This systematic review examined the relationship between pain sensitivity measured via quantitative sensory testing (QST) and self-reported pain or pain-related disability in people with spinal pain. Electronic databases and reference lists were searched. Correlation coefficients for the relationship between QST and pain intensity or disability were pooled using random effects models. Subgroup analyses and mixed effects meta-regression were used to assess whether the strength of the relationship was moderated by variables related to the QST method or pain condition. One hundred and forty-five effect sizes from 40 studies were included in the meta-analysis. Pooled estimates for the correlation between pain threshold and pain intensity were -0.15 (95% confidence interval [CI]: -0.18 to -0.11) and for disability -0.16 (95% CI: -0.22 to -0.10). Subgroup analyses and meta-regression did not provide evidence that these relationships were moderated by the QST testing site (primary pain/remote), pain condition (back/neck pain), pain type (acute/chronic), or type of pain induction stimulus (eg, mechanical/thermal). Fair correlations were found for the relationship between pain intensity and thermal temporal summation (0.26, 95% CI: 0.09 to 0.42) or pain tolerance (-0.30, 95% CI: -0.45 to -0.13), but only a few studies were available. Our study indicates either that pain threshold is a poor marker of central sensitization or that sensitization does not play a major role in patients' reporting of pain and disability. Future research prospects are discussed.

Dry needling - peripheral and central considerations

Dry needling is a common treatment technique in orthopedic manual physical therapy. Although various dry needling approaches exist, the more common and best supported approach targets myofascial trigger points. This article aims to place trigger point dry needling within the context of pain sciences. From a pain science perspective, trigger points are constant sources of peripheral nociceptive input leading to peripheral and central sensitization. Dry needling cannot only reverse some aspects of central sensitization, it reduces local and referred pain, improves range of motion and muscle activation pattern, and alters the chemical environment of trigger points. Trigger point dry needling should be based on a thorough understanding of the scientific background of trigger points, the differences and similarities between active and latent trigger points, motor adaptation, and central sensitize application. Several outcome studies are included, as well as comments on dry needling and acupuncture.