The immediate effectiveness of electrical nerve stimulation and electrical muscle stimulation on myofascial trigger points

Dry needling, trigger point electroacupuncture and motor point electroacupuncture for the treatment of myofascial pain syndrome involving the trapezius: a randomised clinical trial

OBJECTIVE

The objective of this study was to compare trigger point (TrP) dry needling, TrP electroacupuncture and motor point electroacupuncture of the trapezius muscle for the treatment of myofascial pain syndrome (MPS).

METHODS

This randomised clinical trial included 90 patients divided into three groups. Group 1 was treated with dry needling of TrPs, group 2 with intramuscular electrical stimulation of TrPs, and group 3 with electroacupuncture of motor points and/or the spinal accessory nerve. Each group received seven treatment sessions. The outcomes were the pain score measured by visual analogue scale (VAS) and quality of life evaluated by the 12-item short form (SF-12) health questionnaire. We compared the pain outcome over serial time points using growth curve analysis methods.

RESULTS

Participants in the three groups experienced significant improvements in pain scores over time. The average pain level of participants in group 3 across the repeated assessments was 0.98 units lower than in group 1 (mean difference (95% confidence interval (CI) = 1.74-0.23)), p = 0.012). There were no significant differences in pain scores between participants in groups 1 and 2, and there were no significant differences in quality of life across the three groups at the end of the treatment period.

CONCLUSION

Our results provide evidence that electrical stimulation of motor points and/or of the spinal accessory nerve may be superior in terms of pain relief (but not quality of life) to dry needling and possibly electrical stimulation of trigger points for the management of MPS involving the trapezius.

TRIAL REGISTRATION NUMBER

TRIAL-RBR-43R7RF (Brazilian Clinical Trials Registry).

Efficacy of cervical mobilization with post-isometric relaxation in managing mechanical neck pain, ROM, and functional limitations associated with myofascial trigger points

BACKGROUND

Sedentary lifestyle, age-related degenerative changes or traumatic injuries leads to cervical spine structural mal-alignment, which results in neck pain and other symptoms. Various therapeutic exercises and manual techniques have been proven to be beneficial in terms of managing these symptoms. This study aimed to determine the combined effects of cervical mobilization and post-isometric relaxation (PIR) technique on managing neck pain, cervical side flexion range of motion, and functional limitation in participants with mechanical neck pain linked with myofascial trigger points.

METHODS

This study followed a 2-arm, parallel-group, pretest-posttest randomized comparative design. Thirty participants with mechanical neck pain associated with myofascial trigger points aged 30.87 ± 4.45 years were randomly allocated to Groups 1 and 2. Group 1 received conventional intervention, PIR, and cervical mobilization techniques while Group 2 received conventional intervention and PIR technique only. Neck pain, muscle tenderness, cervical range of motion, and functional limitations were assessed using a visual analog scale, pressure pain threshold (PPT), goniometer, and neck disability index (NDI) questionnaire, respectively at baseline on day 1 and post-intervention on day 7, 14, and 21. Wilcoxon signed-rank test and the Mann-Whitney U test evaluated within-group and between-group analyses, respectively. Statistical significance was established at a 95% confidence interval, indicated by P < .05.

RESULTS

Significant differences (95% confidence interval [CI], P < .05) were observed within each group for all the outcomes scores when compared to the baselines across multiple time points. Significant variations were observed between the groups when comparing visual analog scale and NDI scores at weeks 1, 2, and 3 post-interventions. In contrast, insignificant differences (95% CI, P > .05) were observed for side flexion range of motion and PPT compared at weeks 1, 2, and 3 post-interventions except for PPT at week 3 post-intervention (95% CI, P < .05). Additionally, Cohen d test revealed the superiority of group 1 over group 2 in reducing pain and functional limitations and improving cervical side flexion range of motion and PPT.

CONCLUSION

The combination of cervical mobilization and Post-isometric relaxation techniques was discovered to effectively alleviate neck pain and enhance functional abilities when contrasted with the application of post-isometric relaxation alone in patients with mechanical neck pain linked with myofascial trigger points.

Characterising the Features of 381 Clinical Studies Evaluating Transcutaneous Electrical Nerve Stimulation (TENS) for Pain Relief: A Secondary Analysis of the Meta-TENS Study to Improve Future Research

Background and Objectives: Characterising the features of methodologies, clinical attributes and intervention protocols, of studies is valuable to advise directions for research and practice. This article reports the findings of a secondary analysis of the features from studies screened as part of a large systematic review of TENS (the meta-TENS study). Materials and Methods: A descriptive analysis was performed on information associated with methodology, sample populations and intervention protocols from 381 randomised controlled trials (24,532 participants) evaluating TENS delivered at a strong comfortable intensity at the painful site in adults with pain, irrespective of diagnosis. Results: Studies were conducted in 43 countries commonly using parallel group design (n = 334) and one comparator group (n = 231). Mean ± standard deviation (SD) study sample size (64.05 ± 58.29 participants) and TENS group size (27.67 ± 21.90 participants) were small, with only 13 of 381 studies having 100 participants or more in the TENS group. Most TENS interventions were ‘high frequency’ (>10 pps, n = 276) and using 100 Hz (109/353 reports that stated a pulse frequency value). Of 476 comparator groups, 54.2% were active treatments (i.e., analgesic medication(s), exercise, manual therapies and electrophysical agents). Of 202 placebo comparator groups, 155 used a TENS device that did not deliver currents. At least 216 of 383 study groups were able to access other treatments whilst receiving TENS. Only 136 out of 381 reports included a statement about adverse events. Conclusions: Clinical studies on TENS are dominated by small parallel group evaluations of high frequency TENS that are often contaminated by concurrent treatment(s). Study reports tended focus on physiological and clinical implications rather than the veracity of methodology and findings. Previously published criteria for designing and reporting TENS studies were neglected and this should be corrected in future research using insights gleaned from this analysis.

Sitting for Too Long, Moving Too Little: Regular Muscle Contractions Can Reduce Muscle Stiffness During Prolonged Periods of Chair-Sitting

In modern Western societies, sedentary behavior has become a growing health concern. There is increasing evidence that prolonged sitting periods can be associated with musculoskeletal disorders. While it is generally recognized that back muscle activity is low during chair-sitting, little is known about the consequences of minor to no muscle activity on muscle stiffness. Muscle stiffness may play an important role in musculoskeletal health. This study investigated the effects of regular muscle contractions on muscle stiffness in a controlled experiment in which participants sat for 4.5 h. Neuromuscular electrical stimulation in the lumbar region of the back was applied to trigger regular muscle contractions. Using stiffness measurements and continuous motion capturing, we found that prolonged sitting periods without regular muscle contractions significantly increased back muscle stiffness. Moreover, we were able to show that regular muscle contractions can prevent those effects. Our results highlight the importance of consistent muscle activity throughout the day and may help explain why prolonged periods of chair-sitting increase the susceptibility to common pathological conditions such as low back pain.

Masticatory Myofascial Pain Syndrome: Implications for Endodontists

INTRODUCTION

Masticatory myofascial pain syndrome can present similarly to other dental conditions in odontogenetic structures. Endodontists should be familiar with the symptomology and pathophysiology of masticatory myofascial pain syndrome to avoid misdiagnosis, incorrect treatment, and medicolegal repercussions. The aim of this review was to provide a foundational summary for endodontists to identify and correctly manage masticatory myofascial pain syndrome.

METHODS

A narrative review of the literature was performed through a MEDLINE search and a hand search of the major myofascial pain textbooks.

RESULTS

Masticatory myofascial pain syndrome is a musculoligamentous syndrome that can present similarly to odontogenic pain or refer pain to the eyebrows, ears, temporomandibular joints, maxillary sinus, tongue, and hard palate. Currently, the most comprehensive pathophysiology theory describing masticatory myofascial pain syndrome is the expanded integrated hypothesis. The most widely accepted diagnostic guidelines for masticatory myofascial pain syndrome are the Diagnostic Criteria for Temporomandibular Disorders; however, their diagnostic capability is limited. There is no hierarchy of treatment methods because each patient requires a tailored and multidisciplinary management aimed at regaining the muscle's range of motion, deactivating the myofascial trigger points, and maintaining pain relief.

CONCLUSIONS

The pain patterns for masticatory myofascial pain syndrome are well-known; however, there is a lack of consensus on the most proper method of trigger point diagnosis or pain quantification. The diagnostic strategies for masticatory myofascial pain syndrome vary, and the diagnostic aids are not well developed.

Transcutaneous electrical stimulation in neck pain: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

The objective of this systematic review was to investigate the effectiveness of electrical stimulation (ES) for neck pain (NP).

DATABASES AND DATA TREATMENT

The databases CINAHL, Embase, MEDLINE (via OVID), PEDro and Web of Science were searched, with no date restrictions. Two independent reviewers selected randomized controlled trials (RCTs) reporting pain, range of motion or psychosocial factors in people with NP, in which ES was applied. Methodological quality was assessed using the PEDro scale. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) was used to evaluate the quality of evidence. Thirty studies met eligibility criteria.

RESULTS

Main results showed evidence of moderate quality that ES combined with other intervention significantly decreases the pain intensity compared to other intervention immediately post-treatment and at short-term follow-up; evidence of low quality showed significant effects of ES combined with other intervention in decreasing neck disability compared to other intervention immediately post-treatment; evidence of very-low quality that ES increased the pressure pain threshold compared to placebo immediately post-treatment and that ES + other intervention also increased the pressure pain threshold compared to other intervention at short-term follow-up.

CONCLUSIONS

ES combined with other intervention seems to be useful to relieve pain and to improve disability in people with NP, however, more studies are needed.

SIGNIFICANCE

Electrical stimulation seems to be effective for improving pain intensity, immediately post-treatment in people with neck pain, mainly as an adjunct therapeutic modality. Nevertheless, high-quality RCTs are still needed to investigate the efficacy of electrical stimulation in neck pain.

Transcutaneous electrical nerve stimulation (TENS) for chronic neck pain

BACKGROUND

Chronic neck pain is a highly prevalent condition, affecting 10% to 24% of the general population. Transcutaneous electrical nerve stimulation (TENS) is the noninvasive, transcutaneous use of electrical stimulation to produce analgesia. It is a simple, low-cost and safe intervention used in clinical practice as an adjunct treatment for painful musculoskeletal conditions that have a considerable impact on daily activities, such as chronic neck pain. This review is a split from a Cochrane Review on electrotherapy for neck pain, published in 2013, and focuses specifically on TENS for chronic neck pain.

OBJECTIVES

To evaluate the effectiveness of transcutaneous electrical nerve stimulation (TENS) (alone or in association with other interventions) compared with sham and other clinical interventions for the treatment of chronic neck pain.

SEARCH METHODS

We searched Cochrane Back and Neck Trials Register, CENTRAL, MEDLINE, Embase, five other databases and two trials registers to 9 November 2018. We also screened the reference lists of relevant studies to identify additional trials. There were no language, source, or publication date restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) involving adults (≥ 18 years of age) with chronic neck pain (lasting > 12 weeks) that compared TENS alone or in combination with other treatments versus active or inactive treatments. The primary outcomes were pain, disability and adverse events.

DATA COLLECTION AND ANALYSIS

Two independent review authors selected the trials, extracted data and assessed the risk of bias of included studies. A third review author was consulted in case of disagreements. We used the Cochrane 'Risk of bias' tool (adapted by Cochrane Back and Neck), to assess the risk of bias of individual trials and GRADE to assess the certainty of evidence. We used risk ratios (RRs) to measure treatment effects for dichotomous outcomes, and mean differences (MDs) for continuous outcomes, with their respective 95% confidence intervals (CIs).

MAIN RESULTS

We included seven RCTs with a total of 651 participants, mean age 31.7 to 55.5 years, conducted in three different countries (Turkey, Jordan and China). The length of follow-up ranged from one week to six months. Most RCTs used continuous TENS, with a frequency of 60 Hz to 100 Hz, pulse width of 40 μs to 250 μs and tolerable intensity, described as a tingling sensation without contraction, in daily sessions lasting 20 to 60 minutes. Due to heterogeneity in interventions and outcomes, we did not pool individual study data into meta-analyses. Overall, we judged most studies as being at low risk for selection bias and high risk for performance and detection bias. Based on the GRADE approach, there was very low-certainty evidence from two trials about the effects of conventional TENS when compared to sham TENS at short-term (up to 3 months after treatment) follow-up, on pain (assessed by the Visual Analogue Scale (VAS)) (MD -0.10, 95% CI -0.97 to 0.77) and the percentage of participants presenting improvement of pain (RR 1.57, 95% CI 0.84 to 2.92). None of the included studies reported on disability or adverse events.

AUTHORS' CONCLUSIONS

This review found very low-certainty evidence of a difference between TENS compared to sham TENS on reducing neck pain; therefore, we are unsure about the effect estimate. At present, there is insufficient evidence regarding the use of TENS in patients with chronic neck pain. Additional well-designed, -conducted and -reported RCTs are needed to reach robust conclusions.

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.

Analgesic effects of a capacitive-resistive monopolar radiofrequency in patients with myofascial chronic neck pain: a pilot randomized controlled trial

BACKGROUND

To date, there is a lack of prior studies on the use of capacitive resistive monopolar radiofrequency (RF) to treat neck pain. The objective of this study was to investigate the immediate effect of capacitive resistive monopolar radiofrequency (RF=448 kHz), in comparison with a placebo, on (1) reducing neck pain intensity at myofascial trigger points (MTrP), (2) decreasing neck disability and (3) improving cervical range of motion (CROM).

METHODS

A randomized, double-blind, placebo-controlled trial (NCT02353195) was carried out. Patients with myofascial chronic neck pain (N=24) with active MTrP in one upper trapezius muscle were randomly divided into two groups: a radio-frequency group, which received eight sessions of a monopolar capacitive resistive radio-frequency application over the upper trapezius muscle, and a placebo group (PG), which received eight sessions of placebo radio-frequency over the same muscle. Visual analog scale (VAS), CROM and Neck Disability Index (NDI) were evaluated after the first session and after the eight sessions.

RESULTS

The Wilcoxon test for VAS showed statistically significant differences between baseline, immediately after the first session and after eight sessions (p<.001). No significant differences for PG were found. No differences were observed between groups. NDI improved in both groups after eight sessions, but no differences were found between groups (p<.05). ANOVA for time factor showed statistically significant changes in the right cervical rotation in both groups (F=4.112; p=.026) after eight sessions.

CONCLUSIONS

Even though there were no differences between both groups, the monopolar capacitive, resistive RF could have a potential effect on pain intensity.

Superficial Dry Needling and Active Stretching in the Treatment of Myofascial Pain – a Randomised Controlled Trial

A pragmatic, single blind, randomised, controlled trial was conducted to test the hypothesis that superficial dry needling (SDN) together with active stretching is more effective than stretching alone, or no treatment, in deactivating trigger points (TrPs) and reducing myofascial pain.

Forty patients with musculoskeletal pain, referred by GPs for physiotherapy, fulfilled inclusion / exclusion criteria for active TrPs. Subjects were randomised into three groups: group 1 (n=14) received superficial dry needling (SDN) and active stretching exercises (G1); group 2 (n=13) received stretching exercises alone (G2); and group 3 (n=13) were no treatment controls (G3). During the three-week intervention period for G1 and G2, the number of treatments varied according to the severity of the condition and subject/clinician availability. Assessment was carried out pre-intervention (M1), post-intervention (M2), and at a three-week follow up (M3). Outcome measures were the Short Form McGill Pain Questionnaire (SFMPQ) and Pressure Pain Threshold (PPT) of the primary TrP, using a Fischer algometer. Ninety-one per cent of assessments were blind to grouping.

At M2 there were no significant inter-group differences, but at M3, G1 demonstrated significantly improved SFMPQ versus G3 (p=0.043) and significantly improved PPT versus G2 (p=0.011). There were no differences between G2 and G3. The mean PPT and SFMPQ scores correlated significantly in G1 only, though no significant inter-group differences were demonstrated. Numbers of patients requiring further treatment following the trial were: 6 (G1); 12 (G2); 9 (G3). Conclusion: SDN followed by active stretching is more effective than stretching alone in deactivating TrPs (reducing their sensitivity to pressure), and more effective than no treatment in reducing subjective pain. Stretching without prior deactivation may increase TrP sensitivity.

Transcutaneous electrical nerve stimulation for acute pain

BACKGROUND

This is a second update of a Cochrane Review originally published in Issue 2, 2009. Transcutaneous Electrical Nerve Stimulation (TENS) is a non-pharmacological agent, based on delivering low voltage electrical currents to the skin. TENS is used by people to treat a variety of pain conditions.

OBJECTIVES

To assess the analgesic effectiveness of TENS, as a sole treatment, for acute pain in adults.

SEARCH METHODS

We searched the following databases up to 3 December 2014: the Cochrane Central Register of Controlled Trials (CENTRAL), in the Cochrane Library; MEDLINE; EMBASE; CINAHL; and AMED. We also checked the reference lists of included trials.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of adults with acute pain (< 12 weeks) if they examined TENS given as a sole treatment and assessed pain with subjective pain scales. Trials were eligible if they compared TENS to placebo TENS, no treatment controls, pharmacological interventions or non-pharmacological interventions. We excluded trials on experimental pain, case reports, clinical observations, letters, abstracts or reviews. Also we excluded trials investigating the effect of TENS on pain during childbirth (labour), primary dysmenorrhoea or dental procedures. Studies where TENS was given with another treatment as part of the formal trial design were excluded. We did not restrict any articles based on language of publication.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility and carried out study selection, data extraction, 'Risk of bias' assessment and analyses of data. We extracted data on the following: types of participants and pain condition, trial design and methods, treatment parameters, adverse effects, and outcome measures. We contacted trial authors for additional information if necessary.

MAIN RESULTS

We included 12 trials in the original review (2009) and included no further trials in the first update (2011). An additional seven new trials met the inclusion criteria in this second update. In total, we included 19 RCTs involving 1346 participants at entry, with 11 trials awaiting classification either because the full text was unavailable or information in the full text failed to clarify eligibility. We excluded most trials because TENS was given in combination with another treatment as part of the formal study design or TENS was not delivered using appropriate TENS technique. The types of acute pain included in this Cochrane Review were procedural pain, e.g. cervical laser treatment, venepuncture, screening flexible sigmoidoscopy and non-procedural pain, e.g. postpartum uterine contractions and rib fractures. We pooled data for pain intensity for six trials (seven comparisons) comparing TENS with placebo but the I(2) statistic suggested substantial heterogeneity. Mean difference (MD) with 95% confidence intervals (CIs) on a visual analogue scale (VAS, 100 mm) was -24.62 mm (95% CI -31.79 to -17.46) in favour of TENS. Data for the proportion of participants achieving ≥ 50% reduction in pain was pooled for four trials (seven comparisons) and relative risk was 3.91 (95% CI 2.42 to 6.32) in favour of TENS over placebo. We pooled data for pain intensity from five trials (seven comparisons) but the I(2) statistic suggested considerable heterogeneity. MD was -19.05 mm (95% CI -27.30 to -10.79) in favour of TENS using a random-effects model. It was not possible to pool other data. There was a high risk of bias associated with inadequate sample sizes in treatment arms and unsuccessful blinding of treatment interventions. Seven trials reported minor adverse effects, such as mild erythema and itching underneath the electrodes and participants disliking TENS sensation.

AUTHORS' CONCLUSIONS

This Cochrane Review update includes seven new trials, in addition to the 12 trials reviewed in the first update in 2011. The analysis provides tentative evidence that TENS reduces pain intensity over and above that seen with placebo (no current) TENS when administered as a stand-alone treatment for acute pain in adults. The high risk of bias associated with inadequate sample sizes in treatment arms and unsuccessful blinding of treatment interventions makes definitive conclusions impossible. There was incomplete reporting of treatment in many reports making replication of trials impossible.

Trigger points: an anatomical substratum

This study aimed to bring the trapezius muscle knowledge of the locations where the accessory nerve branches enter the muscle belly to reach the motor endplates and find myofascial trigger points (MTrPs). Although anatomoclinical correlations represent a major feature of MTrP, no previous reports describing the distribution of the accessory nerve branches and their anatomical relationship with MTrP are found in the literature. Both trapezius muscles from twelve adult cadavers were carefully dissected by the authors (anatomy professors and medical graduate students) to observe the exact point where the branches of the spinal accessory nerve entered the muscle belly. Dissection was performed through stratigraphic layers to preserve the motor innervation of the trapezius muscle, which is located deep in the muscle. Seven points are described, four of which are motor points: in all cases, these locations corresponded to clinically described MTrPs. The four points were common in these twelve cadavers. This type of clinical correlation between spinal accessory nerve branching and MTrP is useful to achieve a better understanding of the anatomical correlation of MTrP and the physiopathology of these disorders and may provide a scientific basis for their treatment, rendering useful additional information to therapists to achieve better diagnoses and improve therapeutic approaches.

Clinical implication of latent myofascial trigger point

Myofascial trigger points (MTrPs) are hyperirritable points located within a taut band of skeletal muscle or fascia, which cause referred pain, local tenderness and autonomic changes when compressed. There are fundamental differences between the effects produced by the two basic types of MTrPs (active and latent). Active trigger points (ATrPs) usually produce referred pain and tenderness. In contrast, latent trigger points (LTrPs) are foci of hyperirritability in a taut band of muscle, which are clinically associated with a local twitch response, tenderness and/or referred pain upon manual examination. LTrPs may be found in many pain-free skeletal muscles and may be "activated" and converted to ATrPs by continuous detrimental stimuli. ATrPs can be inactivated by different treatment strategies; however, they never fully disappear but rather convert to the latent form. Therefore, the diagnosis and treatment of LTrPs is important. This review highlights the clinical implication of LTrPs.

An ICON Overview on Physical Modalities for Neck Pain and Associated Disorders

INTRODUCTION

Neck pain is common, can be disabling and is costly to society. Physical modalities are often included in neck rehabilitation programs. Interventions may include thermal, electrotherapy, ultrasound, mechanical traction, laser and acupuncture. Definitive knowledge regarding optimal modalities and dosage for neck pain management is limited.

PURPOSE

To systematically review existing literature to establish the evidence-base for recommendations on physical modalities for acute to chronic neck pain.

METHODS

A comprehensive computerized and manual search strategy from January 2000 to July 2012, systematic review methodological quality assessment using AMSTAR, qualitative assessment using a GRADE approach and recommendation presentation was included. Systematic or meta-analyses of studies evaluating physical modalities were eligible. Independent assessment by at least two review team members was conducted. Data extraction was performed by one reviewer and checked by a second. Disagreements were resolved by consensus.

RESULTS

Of 103 reviews eligible, 20 were included and 83 were excluded. Short term pain relief - Moderate evidence of benefit: acupuncture, intermittent traction and laser were shown to be better than placebo for chronic neck pain. Moderate evidence of no benefit: pulsed ultrasound, infrared light or continuous traction was no better than placebo for acute whiplash associated disorder, chronic myofascial neck pain or subacute to chronic neck pain. There was no added benefit when hot packs were combined with mobilization, manipulation or electrical muscle stimulation for chronic neck pain, function or patient satisfaction at six month follow-up.

CONCLUSIONS

The current state of the evidence favours acupuncture, laser and intermittent traction for chronic neck pain. Some electrotherapies show little benefit for chronic neck pain. Consistent dosage, improved design and long term follow-up continue to be the recommendations for future research.

Electrotherapy for neck pain

BACKGROUND

Neck pain is common, disabling and costly. The effectiveness of electrotherapy as a physiotherapeutic option remains unclear. This is an update of a Cochrane review first published in 2005 and previously updated in 2009.

OBJECTIVES

This systematic review assessed the short, intermediate and long-term effects of electrotherapy on pain, function, disability, patient satisfaction, global perceived effect, and quality of life in adults with neck pain with and without radiculopathy or cervicogenic headache.

SEARCH METHODS

We searched CENTRAL, MEDLINE, EMBASE, MANTIS, CINAHL, and ICL, without language restrictions, from their beginning to August 2012; handsearched relevant conference proceedings; and consulted content experts.

SELECTION CRITERIA

Randomized controlled trials (RCTs), in any language, investigating the effects of electrotherapy used primarily as unimodal treatment for neck pain. Quasi-RCTs and controlled clinical trials were excluded.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by The Cochrane Collaboration. We were unable to statistically pool any of the results, but we assessed the quality of the evidence using an adapted GRADE approach.

MAIN RESULTS

Twenty small trials (1239 people with neck pain) containing 38 comparisons were included. Analysis was limited by trials of varied quality, heterogeneous treatment subtypes and conflicting results. The main findings for reduction of neck pain by treatment with electrotherapeutic modalities were as follows.Very low quality evidence determined that pulsed electromagnetic field therapy (PEMF) and repetitive magnetic stimulation (rMS) were more effective than placebo, while transcutaneous electrical nerve stimulation (TENS) showed inconsistent results.Very low quality evidence determined that PEMF, rMS and TENS were more effective than placebo.Low quality evidence (1 trial, 52 participants) determined that permanent magnets (necklace) were no more effective than placebo (standardized mean difference (SMD) 0.27, 95% CI -0.27 to 0.82, random-effects model).Very low quality evidence showed that modulated galvanic current, iontophoresis and electric muscle stimulation (EMS) were not more effective than placebo.There were four trials that reported on other outcomes such as function and global perceived effects, but none of the effects were of clinical importance. When TENS, iontophoresis and PEMF were compared to another treatment, very low quality evidence prevented us from suggesting any recommendations. No adverse side effects were reported in any of the included studies.

AUTHORS' CONCLUSIONS

We cannot make any definite statements on the efficacy and clinical usefulness of electrotherapy modalities for neck pain. Since the evidence is of low or very low quality, we are uncertain about the estimate of the effect. Further research is very likely to change both the estimate of effect and our confidence in the results. Current evidence for PEMF, rMS, and TENS shows that these modalities might be more effective than placebo. When compared to other interventions the quality of evidence was very low thus preventing further recommendations.Funding bias should be considered, especially in PEMF studies. Galvanic current, iontophoresis, EMS, and a static magnetic field did not reduce pain or disability. Future trials on these interventions should have larger patient samples, include more precise standardization, and detail treatment characteristics.

Myofascial pain syndrome: a treatment review

Myofascial pain syndrome (MPS) is defined as pain that originates from myofascial trigger points in skeletal muscle. It is prevalent in regional musculoskeletal pain syndromes, either alone or in combination with other pain generators. The appropriate evaluation and management of myofascial pain is an important part of musculoskeletal rehabilitation, and regional axial and limb pain syndromes. This article reviews the current hypotheses regarding the treatment modalities for myofascial trigger points and muscle pain. Through a critical evidence-based review of the pharmacologic and nonpharmacologic treatments, the authors aim to provide clinicians with a more comprehensive knowledge of the interventions for myofascial pain.

The effect of interactive neurostimulation therapy on myofascial trigger points associated with mechanical neck pain: a preliminary randomized, sham-controlled trial

OBJECTIVES

This trial was conducted to assess the effectiveness of interactive neurostimulation (INS) therapy on the treatment of pain associated with myofascial trigger points (MTPs) in adults with mechanical neck pain.

DESIGN

This was a preliminary, randomized, sham-controlled trial.

SETTING

The trial was conducted in a tertiary-care institution.

SUBJECTS

The participants were 23 adults with pain and MTPs in the neck or shoulder lasting>2 weeks.

INTERVENTIONS

INS (active or sham) was delivered for 10 minutes in a single session over the MTP area in each patient.

OUTCOME MEASURES

Immediately following the intervention, subjects were tested for pressure pain thresholds (PPTs) and 10-cm visual analogue scale score (VAS) for pain intensity. At the 5 day follow-up, two additional tests were performed: the neck disability index (NDI) and the patient specific functional scale (PSFS) for function.

RESULTS

Improvements in function (PSFS) were observed in the treatment group, which were of clinical significance in selected subjects. These effects were statistically greater than those obtained in the sham group but were overall not at a level of clinical significance in this small population. Improvements in pain intensity (VAS) and neck disability (NDI) were observed in both the treatment and sham groups, indicating that INS had no greater benefit using these measures. There was no change in PPTs following either the active or sham treatment.

CONCLUSIONS

INS is a new and emerging therapy, which may be efficacious for managing musculoskeletal conditions, such as myofascial pain syndrome. This study demonstrated improvements in function in individuals with MTPs following INS therapy, which may be of clinical significance in certain patients with neck or shoulder pain. Further large-scale clinical trials are required to confirm this effect and to determine if INS also reduces pain and neck disability.

Complementary and alternative treatment for neck pain: chiropractic, acupuncture, TENS, massage, yoga, Tai Chi, and Feldenkrais

Of the multitude of treatment options for the management of neck pain, no obvious single treatment modality has been shown to be most efficacious. As such, the clinician should consider alternative treatment modalities if a modality is engaging, available, financially feasible, potentially efficacious, and is low risk for the patient. As evidence-based medicine for neck pain develops, the clinician is faced with the challenge of which treatments to encourage patients to pursue. Treatment modalities explored in this article, including chiropractic, acupuncture, TENS, massage, yoga, Tai Chi, and Feldenkrais, represent reasonable complementary and alternative medicine methods for patients with neck pain.

Effects of burst-type transcutaneous electrical nerve stimulation on cervical range of motion and latent myofascial trigger point pain sensitivity

OBJECTIVE

To assess the effects of a burst application of transcutaneous electrical nerve stimulation (TENS) on cervical range of motion and pressure point sensitivity of latent myofascial trigger points (MTrPs).

DESIGN

A single-session, single-blind randomized trial.

SETTING

General community rehabilitation clinic.

PARTICIPANTS

Individuals (N = 76; 45 men, 31 women) aged 18 to 41 years (mean ± SD, 23 ± 4y) with latent MTrPs in 1 upper trapezius muscle.

INTERVENTIONS

Subjects were randomly divided into 2 groups: a TENS group that received a burst-type TENS (pulse width, 200 μs; frequency, 100 Hz; burst frequency, 2 Hz) stimulation over the upper trapezius for 10 minutes, and a placebo group that received a sham-TENS application over the upper trapezius also for 10 minutes.

MAIN OUTCOME MEASURES

Referred pressure pain threshold (RPPT) over the MTrP and cervical range of motion in rotation were assessed before, and 1 and 5 minutes after the intervention by an assessor blinded to subjects' treatment.

RESULTS

The analysis of covariance revealed a significant group × time interaction (P < .001) for RPPT: the TENS group exhibited a greater increase compared with the control group; however, between-group differences were small at 1 minute (0.3 kg/cm²; 95% confidence interval [CI], 0.1-0.4) and at 5 minutes (0.6 kg/cm²; 95% CI, 0.3-0.8) after treatment. A significant group × time interaction (P=.01) was also found for cervical rotation in favor of the TENS group. Between-group differences were also small at 1 minute (2.0°; 95% CI, 1.0-2.8) and at 5 minutes (2.7°; 95% CI, 1.7-3.8) after treatment.

CONCLUSIONS

A 10-minute application of burst-type TENS increases in a small but statistically significant manner the RPPT over upper trapezius latent MTrPs and the ipsilateral cervical range of motion.

Methodological quality in randomised controlled trials of transcutaneous electric nerve stimulation for pain: low fidelity may explain negative findings

The benefits of transcutaneous electrical nerve stimulation (TENS) for pain relief have not been reliably established, as most systematic reviews find poor methodological quality in many studies. The paradox within the evidence base for TENS is that despite identified sources of bias that may lead to an overestimation of treatment effects, no benefits for TENS can be clearly demonstrated. Conventional assessments of quality assume a single direction of bias, and little work has been undertaken examining other directions of bias. Our hypothesis was that low fidelity in studies (bias leading to an underestimation of treatment effects) may account for inconclusive findings. We included 38 studies from 3 recently published Cochrane systematic reviews that examined TENS for acute, chronic, and cancer pain. We extracted data relating to treatment allocation, application of TENS and to the assessment of outcomes. We quantified these data and judged this against standardised assessment criteria using a "traffic light" approach based on the number of studies reaching the standard. We identified significant sources of potential bias in both directions in relation to study design and implementation fidelity that have not been quantified previously. Suboptimal dosing of TENS and inappropriate outcome assessment were particularly prevalent weaknesses indicating low fidelity. We propose criteria for judging directions of bias in future studies of TENS that may be adapted to assess other trials in which implementation fidelity is important, such as other nonpharmacological interventions for pain. Poor implementation fidelity was identified as a significant source of bias in systematic reviews of TENS studies and might explain lack of consistent treatment effects of TENS in pain. Here, criteria for assessing methodology are proposed for use in designing future clinical trials of TENS.

Comparison of miniscalpel-needle release, acupuncture needling, and stretching exercise to trigger point in myofascial pain syndrome

OBJECTIVE

Myofascial pain syndrome (MPS) is one of the most common causes of chronic musculoskeletal pain. Several methods have been recommended for the inactivation of trigger points (TrPs). We carried out this study to investigate the effectiveness of miniscalpel-needle (MSN) release and acupuncture needling and self neck-stretching exercises on myofascial TrPs of the upper trapezius muscle.

METHODS

Eighty-three TrPs in 43 patients with MPS were treated and randomly assigned to 3 groups: group 1 received MSN release in conjunction with self neck-stretching exercises; group 2 received acupuncture needling treatment and performed self neck-stretching exercises; and group 3, the control group, was assigned self neck-stretching exercises only. The therapeutic effectiveness was evaluated using subjective pain intensity (PI) with a visual analog scale, pressure pain threshold (PPT), and contralateral bending range of motion (ROM) of cervical spine at pretreatment, 2 weeks, and 3 months after treatment.

RESULTS

The improvement of PI, PPT, and contralateral bending ROM of cervical spine was significantly greater in group 1 and 2 than that in control group at 2 weeks and 3 months follow-up. Compared with group 2, patients in group 1 had a statistically significant reduction in PI, an increase in PPT, contralateral bending ROM of cervical spine at 3 months follow-up.

DISCUSSION

The effectiveness of MSN release for MPS is superior to that of acupuncture needling treatment or self neck-stretching exercises alone. The MSN release is also safe, without severe side effects in treatment of MPS.

Immediate effect of electric point stimulation (TENS) in treating latent upper trapezius trigger points: a double blind randomised placebo-controlled trial

OBJECTIVE

The purpose of this study was to investigate the immediate effect of electric point stimulation in treating latent upper trapezius trigger points compared to placebo.

DESIGN

Double blind randomised placebo-controlled trial.

SETTING

Anglo-European College of Chiropractic.

PARTICIPANTS

Sixty participants with latent upper trapezius trigger points.

INTERVENTIONS

Electric point stimulator type of TENS, or detuned (inactive) electric point stimulator type of TENS.

MAIN OUTCOME MEASURES

The three outcome measures were pressure pain threshold at the trigger point, a numerical rating scale for pain elicited over the trigger point, and lateral cervical flexion to the side opposite the trigger point.

RESULTS

On the outcome of pressure pain threshold the electric point stimulator group had a mean change of 0.49 (0.99) kg/cm(2), while the placebo group had a mean change of 0.45 (0.98) kg/cm(2) (t = 0.16, df = 58, p = 0.88). For change in pain over the trigger point, the electric point stimulator group had a mean decrease of 0.93 (0.87) points, while the placebo group had a mean decrease of 0.23 (0.97) points (t = 0.70, df = 58, p = 0.005). On the outcome of change in lateral cervical flexion the electric point stimulator group had a mean increase of 2.87 (4.55) degrees, while the placebo group had a mean increase of 1.99 (2.49) degrees (t = 0.92, df = 58, p = 0.36).

CONCLUSION

Electric point stimulator type of TENS is superior to placebo only in reduction of pain for treating latent upper trapezius trigger points.

Electrotherapy for neck pain

BACKGROUND

Neck pain is common, disabling and costly. The effectiveness of electrotherapy as a physiotherapeutic option remains unclear. This update replaces our 2005 Cochrane review on this topic.

OBJECTIVES

To assess whether electrotherapy improves pain, disability, patient satisfaction, and global perceived effect in adults with neck pain.

SEARCH STRATEGY

Computer-assisted searches of: CENTRAL, MEDLINE, EMBASE, MANTIS, CINAHL, and ICL, without language restrictions, from their beginning to December 2008; handsearched relevant conference proceedings; consulted content experts.

SELECTION CRITERIA

Randomised controlled trials in any language, investigating the effects of electrotherapy, used primarily as unimodal treatment for neck pain. Quasi-RCTs and controlled clinical trials were excluded.

DATA COLLECTION AND ANALYSIS

At least two authors independently conducted citation identification, study selection, data abstraction, and risk of bias assessment. We were unable to statistically pool any of the results, but assessed the quality of the evidence using an adapted GRADE approach.

MAIN RESULTS

Eighteen small trials (1043 people with neck pain) with 23 comparisons were included. Analysis was limited by trials of varied quality, heterogeneous treatment subtypes and conflicting results. The main findings for reduction of neck pain by treatment with electrotherapeutic modalities are:Very low quality evidence that pulsed electromagnetic field therapy (PEMF), repetitive magnetic stimulation (rMS) and transcutaneous electrical nerve stimulation (TENS) are more effective than placebo.Low quality evidence that permanent magnets (necklace) are not more effective than placebo.Very low quality evidence that modulated galvanic current, iontophoresis and electric muscle stimulation (EMS) are not more effective than placebo.There were only four trials that reported on other outcomes such as function and global perceived effects, but none were of clinical importance.

AUTHORS' CONCLUSIONS

We cannot make any definite statements on the efficacy and clinical usefulness of electrotherapy modalities for neck pain. Since the quality of evidence is low or very low, we are uncertain about the estimate of the effect. Further research is very likely to change both the estimate of effect and our confidence in the results. Current evidence for PEMF, rMS, and TENS shows that these modalities might be more effective than placebo but not other interventions. Funding bias should be considered, especially in PEMF studies. Galvanic current, iontophoresis, electric muscle stimulation(EMS), and static magnetic field did not reduce pain or disability. Future trials on these interventions should have larger patient samples and include more precise standardization and description of all treatment characteristics.

Knowledge to action: a challenge for neck pain treatment

SYNOPSIS

For clinicians, systematic reviews can enhance incorporation into practice of the large volumes of information emerging from research on effectiveness and risks. But we believe that these reviews are most useful with simplified tools to facilitate translation of this knowledge into practice. We provide a "Neck Care Tool Kit" that gives a diagrammatic approach to prioritizing intervention. The evidence from a series of 11 systematic reviews by the Cervical Overview Group is depicted in decision flow-charts and tables to enhance clinical interpretation of the overview findings. On simple visual inspection of symbols in a table, the reader can establish where there is evidence of benefit or no benefit, the strength of the recommendation, and if these data represent short- or long-term findings. Where possible, we guide clinicians to dosage of specific treatment methods. There is no consensus as to which outcome measures to prioritize among the large number in use. This clinical commentary guides clinicians to view the evidence in enough detail to integrate it into their clinical practice environment. We conclude by delineating research gaps and proposing future research directions.

LEVEL OF EVIDENCE

Therapy, level 5.

Transcutaneous electrical nerve stimulation for acute pain

BACKGROUND

Transcutaneous Electrical Nerve Stimulation (TENS) is a non-pharmacological agent, based on delivering low voltage electrical currents to the skin. TENS is used for the treatment of a variety of pain conditions.

OBJECTIVES

To assess the analgesic effectiveness of TENS for acute pain in adults to see if it had any clear analgesic effect in its own right.

SEARCH STRATEGY

The following databases were searched: Cochrane Pain, Palliative and Supportive Care Group Specialised Register; the Cochrane Central Register of Controlled Trials, CENTRAL (in The Cochrane Library); MEDLINE; EMBASE; CINAHL; AMED; PEDro; OTseeker; OpenSIGLE; and, reference lists of included studies. The most recent search was undertaken in August 2008.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of adults with acute pain (less than 12 weeks) were included if they examined TENS given as a sole treatment and assessed pain with subjective pain scales. Studies were eligible if they compared TENS to placebo TENS, no treatment controls, pharmacological interventions or non-pharmacological interventions. Studies on experimental pain, case reports, clinical observations, letters, abstracts or reviews were excluded. Studies on TENS and labour pain, pain due to dental procedures and primary dysmenorrhoea were excluded. Studies where TENS was given with another treatment as part of the formal study design were also excluded. No restrictions were made regarding language.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial eligibility and extracted data. Data were extracted on the following: types of participants and pain condition, study design and methods, treatment parameters, adverse effects, and outcome measures. Study authors were contacted for additional information if necessary.

MAIN RESULTS

Of 1479 studies identified in the search, 132 were identified as relevant. Of these, 116 were excluded; the vast majority of these were excluded due to TENS being given with another treatment. Four studies were categorised as awaiting classification as the information provided in the full text failed to clarify their eligibility. Twelve RCTs involving 919 participants at entry were included. The types of acute pain conditions included procedural pain, e.g. cervical laser treatment, venipuncture, screening flexible sigmoidoscopy and non-procedural pain, e.g. postpartum uterine contractions, rib fractures. It was not possible to perform a meta-analysis due to insufficient data.

AUTHORS' CONCLUSIONS

Due to insufficient extractable data in the studies included in this review, we are unable to make any definitive conclusions about the effectiveness of TENS as an isolated treatment for acute pain in adults.

Transcutaneous electrical nerve stimulation (TENS) for chronic pain

BACKGROUND

Transcutaneous electrical nerve stimulation (TENS) is a popular pain treatment modality but its effectiveness in chronic pain management is unknown. This review is an update of the original Cochrane review published in Issue 3, 2001.

OBJECTIVES

To evaluate the effectiveness of TENS in chronic pain.

SEARCH STRATEGY

The Cochrane Library, EMBASE, MEDLINE and CINAHL were searched. Reference lists from retrieved reports and reviews were examined. Date of the most recent search: April 2008.

SELECTION CRITERIA

RCTs were eligible if they compared active TENS versus sham TENS controls; active TENS versus 'no treatment' controls; or active TENS versus active TENS controls (e.g. High Frequency TENS (HFTENS) versus Low Frequency TENS (LFTENS)). Studies of chronic pain for three months or more which included subjective outcome measures for pain intensity or relief were eligible for evaluation. No restrictions were made to language or sample size. Abstracts, letters, or unpublished studies, and studies of TENS in angina, headache, migraine, dysmenorrhoea and cancer-related pain were excluded.

DATA COLLECTION AND ANALYSIS

Data were extracted and summarised on the following items: patients and details of pain condition, treatments, study duration, design, methods, subjective pain outcome measures, methodological quality, results for pain outcome measures and adverse effects, and conclusions by authors of the studies. Extracted data and methodological quality of studies were confirmed by the review authors.

MAIN RESULTS

Of 124 studies identified from the searches, 99 did not fulfil pre-defined entry criteria. Twenty-five RCTs involving 1281 participants were evaluated. Included studies varied in design, analgesic outcomes, chronic pain conditions, TENS treatments and methodological quality. The reporting of methods and results for analgesic outcomes were inconsistent across studies and generally poor. Meta-analysis was not possible. Overall in 13 of 22 inactive control studies, there was a positive analgesic outcome in favour of active TENS treatments. For multiple dose treatment comparison studies, eight of fifteen were considered to be in favour of the active TENS treatments. Seven of the nine active controlled studies found no difference in analgesic efficacy between High Frequency (HF) TENS and Low Frequency (LF) TENS.

AUTHORS' CONCLUSIONS

Since the last version of this review, new relevant studies have not provided additional information to change the conclusions. Published literature on the subject lacks the methodological rigour or robust reporting needed to make confident assessments of the role of TENS in chronic pain management. Large multi-centre RCTs of TENS in chronic pain are still needed.

Effect of electroacupuncture on thalamic neuronal response to visceral nociception

The thalamus has been shown to play an important role in somatovisceral integration. This study set out to examine thalamic neuronal responses to visceral nociception when electrical stimulation was applied to the skin receptive field (RF) or to ST(36), an acupoint most frequently used for abdominal pain conventionally. Single neuronal recordings were carried out extracellularly in the thalamic ventrobasal nucleus of anaesthetized rats. Among numerous neurons responding to tactile stimulation, 72 units were found responsive not only to innocuous stimulation on skin RF (60 activated, 12 inhibited) but also to noxious colorectal distension (CRD). Electrical stimulation (2 Hz, 1 mA) of the neuronal somatic receptive field center reduced the subsequent neuronal responses to CRD in 40 neurons tested. High frequency stimulation (100 Hz) produced stronger inhibition than low frequency (2 Hz) stimulation at RF. The inhibition on visceral nociceptive response occurred immediately after the stimulation. In comparison with the effect of RF stimulation, the inhibitory effect was less at either ipsilateral or contralateral ST(36). Our data suggest that, at single thalamic neuron level, stimulation at conventional acupoint is not necessarily as effective as stimulation at neuronal skin receptive field, and high frequency is more effective than low frequency stimulation for the inhibition of visceral nociception.

Neuro Emotional Technique for the treatment of trigger point sensitivity in chronic neck pain sufferers: a controlled clinical trial

BACKGROUND

Trigger points have been shown to be active in many myofascial pain syndromes. Treatment of trigger point pain and dysfunction may be explained through the mechanisms of central and peripheral paradigms. This study aimed to investigate whether the mind/body treatment of Neuro Emotional Technique (NET) could significantly relieve pain sensitivity of trigger points presenting in a cohort of chronic neck pain sufferers.

METHODS

Sixty participants presenting to a private chiropractic clinic with chronic cervical pain as their primary complaint were sequentially allocated into treatment and control groups. Participants in the treatment group received a short course of Neuro Emotional Technique that consists of muscle testing, general semantics and Traditional Chinese Medicine. The control group received a sham NET protocol. Outcome measurements included pain assessment utilizing a visual analog scale and a pressure gauge algometer. Pain sensitivity was measured at four trigger point locations: suboccipital region (S); levator scapulae region (LS); sternocleidomastoid region (SCM) and temporomandibular region (TMJ). For each outcome measurement and each trigger point, we calculated the change in measurement between pre- and post- treatment. We then examined the relationships between these measurement changes and six independent variables (i.e. treatment group and the above five additional participant variables) using forward stepwise General Linear Model.

RESULTS

The visual analog scale (0 to 10) had an improvement of 7.6 at S, 7.2 at LS, 7.5 at SCM and 7.1 at the TMJ in the treatment group compared with no improvement of at S, and an improvement of 0.04 at LS, 0.1 at SCM and 0.1 at the TMJ point in the control group, (P < 0.001).

CONCLUSION

After a short course of NET treatment, measurements of visual analog scale and pressure algometer recordings of four trigger point locations in a cohort of chronic neck pain sufferers were significantly improved when compared to a control group which received a sham protocol of NET. Chronic neck pain sufferers may benefit from NET treatment in the relief of trigger point sensitivity. Further research including long-term randomised controlled trials for the effect of NET on chronic neck pain, and other chronic pain syndromes are recommended.

TRIAL REGISTRATION

This trial has been registered and allocated the Australian Clinical Trials Registry (ACTR) number ACTRN012607000358448. The ACTR has met the requirements of the ICMJE's trials registration policy and is an ICMJE acceptable registry.