Effects of the carrier frequency of interferential current on pain modulation and central hypersensitivity in people with chronic nonspecific low back pain: A randomized placebo-controlled trial

Acute and long-term effect of specific and non-specific exercises in patients with chronic neck pain: A protocol for a randomized controlled trial

Exercise therapy is the most common approach for people with chronic neck pain (CNP). Although well-established, it remains unknown which type of exercise is the best for treating this condition. Moreover, pain processing can play a role in the persistence of pain and in the response to interventions. Thus, the aim of this randomized controlled trial is to compare the acute and long-term effects of two exercise protocols (specific and non-specific) on pain and pain processing in individuals with CNP. One hundred and ten participants aged between 18 and 65 years who have had non-specific neck pain for more than 3 months will be recruited. They will be randomized and allocated into two groups (specific exercises and non-specific exercises) and both groups will perform an exercise programme twice a week for 8 weeks. Both programmes are divided into two progressive and individualized phases. The primary outcomes are change in pain intensity after 8 weeks of exercise and exercise-induced hypoalgesia, and secondary outcomes are pressure pain threshold, temporal summation of pain, conditioned pain modulation, the Neck Disability Index, the Baecke Physical Activity Questionnaire, and the Global Perception of Change Scale. Outcomes will be assessed at baseline, after 8 weeks of intervention, and at 6-month follow-up.

Pain profiles and variability in temporal summation of pain and conditioned pain modulation in pain-free individuals and patients with low back pain, osteoarthritis, and fibromyalgia

BACKGROUND

Pain profiles (e.g. pro- and anti-nociceptive) can be developed using quantitative sensory testing (QST) but substantial variability exists. This study describes the variability in temporal summation of pain (TSP) and conditioned pain modulation (CPM) in chronic musculoskeletal pain patients, proposes cut-off values, and explores the association with clinical pain intensity.

METHODS

This is a secondary analysis in which TSP and CPM were assessed using cuff algometry in pain-free subjects (n = 69), and patients with chronic low back pain (cLBP, n = 267), osteoarthritis (n = 134), and fibromyalgia (n = 101). Using TSP and CPM from the pain-free subjects as a reference, four distinct pain profiles TSP (low/high) and CPM (low/high) were created, and differences in clinical pain between pain profiles were explored.

RESULTS

Individual data revealed large inter-person variability. High TSP and low CPM were found in fibromyalgia (p < 0.01) and osteoarthritis (p < 0.01) but not cLBP when compared to pain-free subjects. The proportion of patients classified into the distinct pain profiles was significantly different (p < 0.001) with the largest proportion in the high TSP and low CPM group in fibromyalgia (52.5%) and osteoarthritis (41.4%). Clinical pain was not significantly different comparing the pain profiles, and no significant correlations were observed between clinical pain and TSP or CPM.

CONCLUSION

These results demonstrated substantial inter-person variability in TSP and CPM in patients with different chronic pain conditions and pain-free subjects. The proportion of patients with a pro-nociceptive profile appears larger in fibromyalgia and osteoarthritis, but we found no association to clinical pain.

SIGNIFICANT STATEMENT

This analysis shows that there is variability when assessing TSP and CPM in both pain-free subjects and patients with chronic pain. A cut-off for determining when a person is pain-sensitive is proposed, and data based on this cut-off approach suggest that significantly more patients with osteoarthritis and fibromyalgia are pain-sensitive (i.e. higher TSP and lower CPM) compared to pain-free subjects. This analysis does not find an association between pain sensitivity and clinical pain.

Effectiveness of interferential current in patients with chronic non-specific low back pain: a systematic review with meta-analysis

BACKGROUND

There is no systematic review assessing the effectiveness of interferential current (IC) in patients with low back pain.

OBJECTIVE

To investigate the effectiveness of IC in patients with chronic non-specific low back pain.

METHODS

The databases PUBMED, EMBASE, PEDro, Cochrane Library, CINAHL, and SCIELO were searched. Randomized controlled trials reporting pain intensity and disability in patients with chronic non-specific low back pain, in which IC was applied were included. 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.

RESULTS

Thirteen RCTs were considered eligible for this systematic review (pooled n = 1367). Main results showed moderate-quality evidence and moderate effect sizes that IC probably reduces pain intensity and disability compared to placebo immediately post-treatment (Pain: MD = -1.57 points; 95% CI -2.17, -0.98; Disability: MD = -1.51 points; 95% CI -2.57, -0.46), but not at intermediate-term follow-up. Low-quality evidence with small effect size showed that IC may reduce pain intensity (SMD = -0.32; 95% CI -0.61, -0.03, p = 0.03) compared to TENS immediately post-treatment, but not for disability. There is very low-quality evidence that IC combined with other interventions (massage or exercises) may not further reduce pain intensity and disability compared to the other interventions provided in isolation immediately post-treatment.

CONCLUSION

Moderate-quality evidence shows that IC is probably better than placebo for reducing pain intensity and disability immediately post-treatment in patients with chronic non-specific low back pain.

Evidence- and data-driven classification of low back pain via artificial intelligence: Protocol of the PREDICT-LBP study

In patients presenting with low back pain (LBP), once specific causes are excluded (fracture, infection, inflammatory arthritis, cancer, cauda equina and radiculopathy) many clinicians pose a diagnosis of non-specific LBP. Accordingly, current management of non-specific LBP is generic. There is a need for a classification of non-specific LBP that is both data- and evidence-based assessing multi-dimensional pain-related factors in a large sample size. The "PRedictive Evidence Driven Intelligent Classification Tool for Low Back Pain" (PREDICT-LBP) project is a prospective cross-sectional study which will compare 300 women and men with non-specific LBP (aged 18-55 years) with 100 matched referents without a history of LBP. Participants will be recruited from the general public and local medical facilities. Data will be collected on spinal tissue (intervertebral disc composition and morphology, vertebral fat fraction and paraspinal muscle size and composition via magnetic resonance imaging [MRI]), central nervous system adaptation (pain thresholds, temporal summation of pain, brain resting state functional connectivity, structural connectivity and regional volumes via MRI), psychosocial factors (e.g. depression, anxiety) and other musculoskeletal pain symptoms. Dimensionality reduction, cluster validation and fuzzy c-means clustering methods, classification models, and relevant sensitivity analyses, will classify non-specific LBP patients into sub-groups. This project represents a first personalised diagnostic approach to non-specific LBP, with potential for widespread uptake in clinical practice. This project will provide evidence to support clinical trials assessing specific treatments approaches for potential subgroups of patients with non-specific LBP. The classification tool may lead to better patient outcomes and reduction in economic costs.

The effect of transcutaneous electrical nerve stimulation on pain and electrical stimulation muscle thickness in patients with non-specific chronic low back pain-based ultrasonographic evaluation

Aim: The existing mechanisms of transcutaneous electrical nerve stimulation (TENS) focuses more on the effect of neural tissue. This study investigated the effect of TENS on the thickness of the erector spinae muscles and reducing pain. Patients & methods: 56 individuals with low back pain participated in this single-blind, pre/post-test study. For 2 weeks, participants underwent ten sessions of TENS. The ultrasound evaluations examined the thickness of the erector spinae muscle, and the visual analog scale measured the severity of low back pain. Results: There was a decrease in pain score and muscle thickness after the interventions (p ≤ 0.004). There was also a strong correlation between reducing pain and decreasing muscle thickness (R = 0.709; p = 0.000). Conclusion: Following TENS in the lumbar, in addition to reducing pain, the thickness of the erector spinae muscles also decreased. Clinical Trial Registration: IRCT20200423047173N1 (ClinicalTrials.gov).

Efficacy of Transcutaneous Electrical Nerve Stimulation and Interferential Current on Tactile Acuity of Individuals With Nonspecific Chronic Low Back Pain

OBJECTIVES

Transcutaneous electrical nerve stimulation (TENS) and interferential currents (IFC) are pain electrotherapies with questioned efficacy. Studies of their effects on tactile acuity of individuals with nonspecific chronic low back pain (NSCLBP) are limited, hence, this study.

MATERIALS AND METHODS

Thirty-three individuals with NSCLBP randomly allocated into three groups completed this study. Data collected from participants included age, gender, and anthropometric characteristics of height, weight, body mass index, and percentage body fat measured with standard instruments. Also, participants' tactile acuity, pain intensity, and disability were assessed before and after interventions with digital caliper, numerical pain rating scale, and Roland-Morris Disability Questionnaire, respectively. Interventions consisted of stretching, strengthening, and stabilization exercises to all three groups in addition of TENS to group 1 and IFC to group 2, respectively, for five weeks. Descriptive statistics of mean and standard deviation summarized the data. Inferential statistics of paired t-test, independent t-test, and analysis of variance tested the level of significance among variables at p ≤ 0.05.

RESULTS

Tactile acuity was significantly (p < 0.05) increased after TENS intervention only, while pain intensity was significantly (p < 0.05) reduced after the three interventions. The result showed no gender difference in tactile acuity values among the participants.

CONCLUSIONS

TENS increases the tactile acuity of individuals with NSCLBP, whereas IFC demonstrated no significant change in tactile acuity.

Autonomic Nervous System Function and Central Pain Processing in People With Frozen Shoulder: A Case-control Study

OBJECTIVES

The pathophysiology of a frozen shoulder (FS) is thought to be related to chronic inflammation. Chronic inflammation may disturb the immune system and consequently the nervous system as part of an overarching system. The aim of this study was to determine the presence of disturbed autonomic nervous system function and altered central pain processing (CPP) in patients with FS. Secondarily, the presence of psychological variables (catastrophizing and hypervigilance) and self-reported associated symptoms of altered CPP in patients with FS were investigated.

METHODS

Patients with FS and healthy controls completed the Composite Autonomic Symptom Score (autonomic function) and underwent quantitative sensory testing to assess tactile sensitivity (ie, allodynia), pressure pain thresholds (PPTs, ie, hyperalgesia), temporal summation of pain, and Conditioned Pain Modulation (CPM). Psychological issues were explored with the Pain Catastrophizing Scale and the Pain Vigilance and Awareness Questionnaire, and self-reported symptoms associated with altered CPP were determined with the Central Sensitization Inventory.

RESULTS

Thirty-two patients with FS and 35 healthy controls were analyzed in the study. Patients with FS showed more self-reported autonomic symptoms and symptoms of altered CPP, higher levels of pain catastrophizing and hypervigilance, and are more sensitive to tactile touches and mechanical pressure compared with controls.

DISCUSSION

On the basis of the effect sizes, between-group differences in allodynia, hyperalgesia, catastrophizing, and hypervigilance were clinically relevant, but only local allodynia, hyperalgesia, catastrophizing, and hypervigilance were statistically different. Therefore, obvious altered CPP was not present at the group level in patients with FS compared with controls.

Neuroendocrine effects of a single bout of functional and core stabilization training in women with chronic nonspecific low back pain: A crossover study

Exercise-induced hypoalgesia (EIH) is characterized as the pain reduction after an exercise session and it seems to be related to the release of plasma β-endorphin. In this sense, the core stabilization training (CT) has been suggested for patients with chronic nonspecific low back pain (CNSLBP), but it is unclear whether it induces EIH. Patients with CNSLBP have neuromotor dysfunctions that can affect the performance of functional tasks, thus, performing functional training (FT) could improve motor control and promote EIH, since functional training uses multi-joint exercises that aim to improve the functionality of actions performed in daily life. EIH is usually assessed using quantitative sensory tests (QST) such as conditioned pain modulation, pressure pain threshold, and temporal summation. Thus, the sum of parameters from quantitative sensory tests and plasma β-endorphin would make it possible to understand what the neuroendocrine effects of FT and CT session are. Our study compared the acute effect of CT and FT on the EIH and plasma β-endorphin release, and correlated plasma β-endorphin with quantitative sensory testing in patients with CNSLBP. Eighteen women performed two training sessions (CT and FT) with an interval of 48 h between sessions. EIH was assessed by QST and plasma β-endorphin levels. Results showed that only FT significantly increased plasma β-endorphin (FT p < 0.01; CT p = 0.45), which correlated with pain pressure threshold (PPT) and conditioned pain modulation (CPM). However, QST values were not different in women with CNSLBP after CT or FT protocols. Plasma β-endorphin correlated with PPT and CPM, however, the same did not occur with a temporal summation.

A Systematic Review and Meta-analysis Investigating the Pain-Relieving Effect of Interferential Current on Musculoskeletal Pain

BACKGROUND

Interferential current is one of the most common electrotherapeutic modalities used in the treatment of painful conditions. Patients seeking medical help to reduce their musculoskeletal pain can be treated using interferential current.

OBJECTIVE

The current review aimed to analyze the recently available information regarding the efficacy of interferential current in alleviating the pain of musculoskeletal origin.

METHODS

This study used Scopus, CINAHL, Cochrane Library, Web of Science, MEDLINE, Embase, and EBSCOas as data sources. The initial selection of the studies, thorough assessment of the full articles, and extraction of the necessary study characteristics were carried out by two independent reviewers. Another two independent reviewers assessed the methodological quality of each included trial against 39 criteria. These criteria were integrated from several popular scales. Pain intensity-measured using the visual analog scale, numeric pain rating scale, or McGill Pain Questionnaire-was the outcome of interest.

RESULTS

This review included 35 trials of variable methodological quality from which 19 trials were selected for the meta-analysis. In general, interferential current alone versus placebo demonstrated a significant pain-relieving effect. On the other hand, interferential current showed no significant difference when added to standard treatment compared with placebo plus standard treatment or standard treatment alone. Similarly, interferential current showed no significant difference when compared with other single interventions (laser, transcutaneous electrical nerve stimulation, cryotherapy).

CONCLUSIONS

Interferential current alone is better than placebo at discharge. However, the low number of studies raises suspicions about this conclusion. Interferential current alone or added to other interventions is not more effective than comparative treatments in relieving musculoskeletal pain.

Traditional acupuncture and laser acupuncture in chronic nonspecific neck pain: study protocol for a randomized controlled trial

Background

Nonspecific neck pain is a multifactorial and very common condition in adult individuals, traditional acupuncture (TA) and laser acupuncture (LA) may be treatment options for certain individuals in such a condition. However, no reports were found in the literature comparing the effectiveness of TA and LA in cases of chronic nonspecific neck pain. Therefore, the aim of the present study is to investigate the effectiveness of TA and LA therapies in individuals with chronic nonspecific neck pain, noting which one is more efficient for this condition. The result of this research will have direct implications for pain management and, consequently, may benefit individuals suffering from nonspecific chronic neck pain.

Methods/design

This will be a controlled and randomized clinical trial. Eighty-four individuals will be recruited and distributed equally and randomly into 3 groups: TA (which will receive the acupuncture treatment with needles), LA (which will receive the laser acupuncture treatment), and Sham (who will receive the placebo intervention). The acupuncture points (Tianzhu, Fengchi, Jianjing, and Jianzhongshu) will be stimulated bilaterally. The primary outcome will be pain intensity, determined using the Numerical Rating Scale. The secondary outcomes will be pressure pain threshold, temporal summation of pain, conditioned pain modulation, use of analgesic medicines after treatment, and the global perceived effect scale. The assessments will be performed immediately before and after the treatment, which will be a single session, at the follow-up and 1 month after the end of the treatments; evaluation will be made of the pain intensity and the global perceived effect. Statistical analysis of the data obtained will consider a significance level of p < 0.05.

Discussion

This study will provide evidence concerning the effects of LA treatment, in comparison with TA and sham intervention, leading to benefits for individuals suffering from chronic nonspecific neck pain.

Trial registration

Brazilian Registry of Clinical Trials - ReBEC RBR-7vbw5gd. Date of registration: August 06th, 2021.

Analgesic Effects of Interferential Current Therapy: A Narrative Review

Background and Objectives: Transcutaneous electrical stimulation of low- and medium-frequency currents is commonly used in pain management. Interferential current (IFC) therapy, a medium frequency alternating current therapy that reportedly reduces skin impedance, can reach deeper tissues. IFC therapy can provide several different treatment possibilities by adjusting its parameters (carrier frequency, amplitudemodulated frequency, sweep frequency, sweep mode or swing pattern, type of application (bipolar or quadripolar), time of application and intensity). The objective of this review article is to discuss the literature findings on the analgesic efficacy of IFC therapy. Conclusions: According to the literature, IFC therapy shows significant analgesic effects in patients with neck pain, low back pain, knee osteoarthritis and post-operative knee pain. Most of the IFC parameters seem not to influence its analgesic effects. We encourage further studies to investigate the mechanism of action of IFC therapy.

IMMEDIATE ANALGESIC EFFECT OF 4KHZ AMFS INTERFERENTIAL CURRENT ON CHRONIC LOW BACK PAIN

ABSTRACT Objective: To analyze the immediate effect of amplitude modulation frequencies (AMFs) of 4kHz interferential current (IFC) on chronic low back pain (CLBP). Method: This is a randomized controlled clinical trial. Sixty-three subjects with CLBP were recruited. The subjects were randomized into 3 groups: the placebo group (PG, n=21) and 2 intervention groups (IG), IG4kHz/2Hz (n=21) and IG4kHz/100Hz (n=21). All groups were submitted to a single session of 30 minutes. Pain was evaluated using a numerical rating scale (NRS), the McGill Pain Questionnaire (MPQ), and pressure algometry. Flexibility was evaluated using the Modified Schober Test (MST), the Sit-and-Reach Test (SRT), the Fingertip-to-Floor Test (FTF), and the Passive Straight-Leg Raise Test (PSLR). Results: Comparing IG4kHz/100Hz with PG, we found a significant difference (p<0.05) in NRS in the total and in the MPQ categories, whereas in the comparison between IG4kHz/2Hz and PG, we found a significant difference only in the sensory and evaluative categories of MPQ. Regarding the flexibility tests, we observed a significant difference of both IG4kHz/100Hz and IG4kHz/2Hz in comparison to PG in MST and PSLR, and of IG4kHz/2Hz in comparison to PG in SRT. The 4kHz IFC was effective in immediately reducing CLBP and, consequently, in increasing the flexibility of the lumbar spine and lower limbs. Conclusion: Conclusion: There was a greater number of significant positive outcomes when the 100Hz AMF was adopted. Level of Evidence I; High quality randomized clinical trial with or without statistically significant differences, but with narrow confidence intervals.

Deprescribing paracetamol in pain conditions: A scoping review

OBJECTIVE

To examine evidence on deprescribing paracetamol in pain conditions and inform future strategies for paracetamol deprescription.

DESIGN

Scoping review.

PARTICIPANTS

Adults with pain conditions, taking paracetamol.

RESULTS

After two independent teams of reviewers screening for titles, abstracts, and then full texts, 16 original articles were included. Deprescribing strategies were grouped into 5 categories: (1) Pharmacological, (2) Psychological, (3) Physiological, (4) Policy, and (5) Combination. We found strategies were predominately consumer-focused, conducted in community settings and involved individuals experiencing musculoskeletal pain (such as low back pain and osteoarthritis). A total of twelve studies investigated interventions targeting dose reduction and four studies examined interventions focusing on discontinuation of paracetamol. The most common strategies used to deprescribe paracetamol in pain conditions were physiological strategies, followed by psychological strategies. All included studies demonstrated some level of effectiveness to deprescribe paracetamol in a pain conditions through dose reduction or discontinuation, although the effectiveness of deprescribing strategies were highly variable, ranging from the majority of participants discontinuing their paracetamol use, to less than 10% reducing their paracetamol use upon the latest follow-up.

CONCLUSIONS

There are clear opportunities for prospective trials to be designed more purposely and primarily focused to influence reduction and cessation of paracetamol for specific pain conditions where deprescription is appropriate.

Sensory, Motor, and Psychosocial Characteristics of Individuals With Chronic Neck Pain: A Case-Control Study

OBJECTIVE

Given the complex and unclear etiology of neck pain, it is important to understand the differences in central sensitization as well as psychosocial factors in individuals with chronic neck pain and healthy controls. The purpose of this study was to benchmark differences in central sensitization, psychosocial factors, and range of motion between people with nonspecific chronic neck pain and healthy controls and to analyze the correlation between pain intensity, neck disability, and psychosocial factors in people with chronic neck pain.

METHODS

Thirty individuals with chronic neck pain and 30 healthy controls were included in this case-control study. Outcome measures were as follows: central sensitization (pressure pain threshold, temporal summation, and conditioned pain modulation), psychosocial factors (depressive symptoms, pain catastrophizing, and quality of life), and active cervical range of motion.

RESULTS

People with neck pain had lower local pressure pain threshold, a decrease in conditioned pain modulation, more depressive symptoms, greater pain catastrophizing, lower quality of life, and reduced range of motion for neck rotation when compared with healthy controls. In people with neck pain, moderate correlations were observed between pain intensity and quality of life (ρ = -0.479), disability and pain catastrophizing (ρ = 0.379), and disability and quality of life (ρ = -0.456).

CONCLUSIONS

People with neck pain have local hyperalgesia, impaired conditioning pain modulation, depressive symptoms, pain catastrophizing, low quality of life, and reduced active range of motion during neck rotation, which should be taken into account during assessment and treatment.

IMPACT

This study shows that important outcomes, such as central sensitization and psychosocial factors, should be considered during assessment and treatment of individuals with nonspecific chronic neck pain. In addition, pain intensity and neck disability are correlated with psychosocial factors.

Immediate analgesic effect of transcutaneous electrical nerve stimulation (TENS) and interferential current (IFC) on chronic low back pain: Randomised placebo-controlled trial

OBJECTIVE

To compare the immediate analgesic effect of transcutaneous nerve stimulation (TENS) and interferential current (IFC), with different combinations of parameters, in individuals with chronic low back pain (CLBP).

METHODOLOGY

280 individuals with CLBP were included in the study, both genders, randomized in 8 groups: GI2KHz/100Hz, GI2KHz/2Hz, GI4KHz/100Hz, GI4KHz/2Hz, placebo interferential group (GIP), GT100Hz, GT2Hz, and placebo TENS group (GTP). All individuals underwent a single application of TENS or IFC for 30min. The assessments were carried out prior to the intervention, as well as immediately after, with the following outcomes: pain intensity (Numeric Pain Rating Scale-NPRS), qualitative pain characteristics (McGill Pain Questionnaire-MPQ), and pressure pain threshold (PPT) by pressure algometry (PA) in 4 points of the low back region.

RESULTS

In the intergroup comparison of NPRS, all intervention groups showed greater pain reduction compared to GTP (p < 0.05). In the total MPQ score, the groups that obtained significant results (p < 0.05) when compared to GTP were GT100Hz and GT2Hz, while the groups GT100Hz and GI4KHz/100Hz were significant when compared to GIP. In the PA, GI4KHz/100Hz showed an increase in the PPT in all points compared to GTP and GI2KHz/100Hz.

CONCLUSION

Both TENS and IFC presented immediate analgesic effect in CLBP, with emphasis on the interferential current of 4 KHz modulated at 100Hz.

Effect of Pain Education, Cryotherapy, and Transcutaneous Electrical Nerve Stimulation on the Pain, Functional Capacity, and Quality of Life in Patients With Nonspecific Chronic Low Back Pain: A Single-Blind Randomized Controlled Trial

OBJECTIVE

The aim of the study was to analyze the effects of pain education and the combined use of cryotherapy and transcutaneous electrical nerve stimulation on the pain sensation, functional capacity, and quality of life of patients with nonspecific chronic low back pain.

DESIGN

This is a randomized controlled and blind clinical trial including patients with nonspecific chronic low back pain in the following 4 groups: control group, cryotherapy group, burst transcutaneous electrical nerve stimulation group, and cryotherapy combined with burst transcutaneous electrical nerve stimulation group. They were evaluated at baseline and after the protocol was concluded using the following: Roland-Morris questionnaire and sit-to-stand test; quality-of-life questionnaire; and pain. The protocol consisted of 10 sessions with pain education associated the combination of the electrophysical agents.

RESULTS

There were no statistical differences between groups after the intervention protocol. In the within analysis, all groups presented an improvement in visual analog scale scores, Roland-Morris questionnaire, sit-to-stand test, and pain domain of quality-of-life questionnaire.

CONCLUSIONS

This study showed that with pain education, there was no difference between cryotherapy and transcutaneous electrical nerve stimulation alone, combined, or placebo mode in improving pain, functional capacity, and quality of life in patients with nonspecific chronic low back pain.

Alterations in pronociceptive and antinociceptive mechanisms in patients with low back pain: a systematic review with meta-analysis

Altered pronociceptive and antinociceptive mechanisms are often implicated in painful conditions and have been increasingly studied over the past decade. For some painful conditions, alterations are well-established, but in populations with low back pain (LBP), there remains considerable debate whether these mechanisms are altered. The present systematic review aimed to address this issue by identifying studies assessing conditioned pain modulation (CPM) and/or temporal summation of pain (TSP) in patients with LBP, comparing with either a healthy control group or using a method with reference data available. Qualitative synthesis and quantitative meta-analysis of group differences were performed. For CPM and TSP, 20 and 29 original articles were eligible, with data for meta-analysis obtainable from 18 (1500 patients and 505 controls) and 27 (1507 patients and 1127 controls) studies, respectively. Most studies were of poor-to-fair quality with significant heterogeneity in study size, population, assessment methodology, and outcome. Nonetheless, CPM was impaired in patients with LBP compared with controls (standardized mean difference = -0.44 [-0.64 to -0.23], P < 0.001), and the magnitude of this impairment was related to pain chronicity (acute/recurrent vs chronic, P = 0.003), duration (RS = -0.62, P = 0.006), and severity (RS = -0.54, P = 0.02). Temporal summation of pain was facilitated in patients with LBP compared with controls (standardized mean difference = 0.50 [0.29-0.72], P < 0.001), and the magnitude of this facilitation was weakly related to pain severity (RS= 0.41, P = 0.04) and appeared to be influenced by test modality (P < 0.001). Impaired CPM and facilitated TSP were present in patients with LBP compared with controls, although the magnitude of differences was small which may direct future research on the clinical utility.

Correlation of pain sensitization with muscle strength and angular kinematics in women with patellofemoral pain

BACKGROUND

Patellofemoral pain has a poor long-term prognosis, which can be explained by a pain sensitization process. The pain sensitization process may be related to the increase of stress in the patellofemoral joint that is already associated with kinematic alterations and weakness in the musculature of the hip and knee.

METHODS

Were compared the pressure pain threshold, temporal summation, conditioned pain modulation, angular kinematics, and muscle strength between 26 patellofemoral pain and 24 asymptomatic women and then correlated pain sensitization variables with biomechanical variables in pain group. The pressure pain threshold was determined on seven points of the knee, tibialis anterior muscle, and elbow. Ten consecutive stimuli were performed for temporal summation, and cold water was used as the conditioning stimulus for conditioned pain modulation. The strength of hip and knee muscles was determined using a manual dynamometer. Three-dimensional kinematics were evaluated during the lateral step down, considering peak and excursion values of the movement and the Movement Deviation Profile.

FINDINGS

The pressure pain threshold of the elbow (2.13 [1.84-2.41] vs. 1.63 [1.25-2] kg/cm²), all sites of the knee were lower, as well as the Movement Deviation Profile was higher (9.33 [9.20-9.46] vs. 12.43 [12.1-12.75]) in the pain group. No difference in temporal summation, conditioned pain modulation, muscle strength and discrete kinematic values were found. No significant correlation was found between the Movement Deviation Profile and pressure pain threshold.

INTERPRETATION

Biomechanical factors, pain processing, and modulation in women with patellofemoral pain, when different from asymptomatic individuals, are not necessarily associated.

Association of thoraco-lumbar fascia length in individuals with non-specific low back pain - an observational study

OBJECTIVE

The purpose of the study was to assess the length of TLF and to evaluate the strength of muscles attached to it in subjects with and without nonspecific low back pain (NSLBP).

METHODS

31 patients with NSLBP and 31 healthy individuals were included in the study. In each subject the TLF length was assessed by quantifying lumbar rotation using Back range of motion (BROM-II) instrument. The endurance of transverses abdominis was assessed using the pressure biofeedback unit while the strength of Latissimus dorsi, internal and external oblique's were assessed using MMT. Outcome measure such as Range of Motion (ROM) was compared across the group using independent sample T-test. While the muscle strength of Latissimus dorsi and oblique's were compared across the group using Man-whitney U- test. Transverse abdominis endurance was tested using chi-square test.

RESULTS

There was statistically significant difference in the length of TLF of subjects with NSLBP when compared with subjects without NSLBP. When the strength of Latissimus dorsi muscle, transverses abdominis muscle and internal and external oblique's muscle was assessed no significant (p value > 0.05) difference was found in either group.

CONCLUSIONS

There was statistically significant reduction in length of TLF but there was no difference in the strength of Latissimus dorsi, internal and external oblique's or endurance of transverses abdominus attached to the TLF in individuals with NSLBP and without low back pain. This study will help in determining the inclusion of TLF and the associated structures in evaluation and management of subjects with NSLBP.

Efficacy of Physical Therapy on Nociceptive Pain Processing Alterations in Patients with Chronic Musculoskeletal Pain: A Systematic Review and Meta-analysis

INTRODUCTION

Chronic musculoskeletal pain is a major health, social, and economic problem. Most of the subjects who suffer from chronic musculoskeletal pain present processes of central sensitization. Temporal summation and conditioned pain modulation are the two most commonly used clinical measures of this. The objective of this review is to evaluate the effects of physical therapy on temporal summation (TS) and conditioned pain modulation (CPM) in patients with chronic musculoskeletal pain.

METHODS

This is a systematic review and meta-analysis. We searched the MEDLINE, EMBASE, CINAHL, EBSCO, PubMed, PEDro, Cochrane Collaboration Trials Register, Cochrane Database of Systematic Reviews, and SCOPUS databases. Different mesh terms and key words were combined for the search strategy, with the aim of encompassing all studies that have used any type of physical therapy treatment in patients with chronic musculoskeletal pain and have measured both TS and CPM.

RESULTS

Eighteen studies remained for qualitative analysis and 16 for quantitative analysis. Statistically significant differences with a 95% confidence interval (CI) were obtained for TS (-0.21, 95% CI = -0.39 to -0.03, Z = 2.50, P = 0.02, N = 721) and CPM (0.34, 95% CI = 0.12 to 0.56, Z = 2.99, P = 0.003, N = 680) in favor of physical therapy as compared with control. Manual therapy produces a slight improvement in TS, and physical therapy modalities in general improve CPM. No significant differences between the subgroups of the meta-analysis were found. The methodological quality of the studies was high.

CONCLUSIONS

Physical therapy produces a slight improvement in central sensitization (CS)-related variables, with TS decreased and CPM increased when compared with a control group in patients with CMP. Only significant differences in TS were identified in the manual therapy subgroup.

Photobiomodulation therapy and transcutaneous electrical nerve stimulation on chronic neck pain patients: Study protocol clinical trial (SPIRIT Compliant)

INTRODUCTION

Chronic neck pain is a common musculoskeletal disorder that is associated with functional disability and decreased of quality of life. Electrophysical agents are commonly used to relieve pain, however the effects of combined use of these agents are little studied. The objective is to investigate the efficacy of photobiomodulation and electrical stimulation to relieve pain, both in isolation and combined.

MATERIALS AND METHODS

This a 4-arm randomized placebo-controlled trial with patient and evaluator blinded. This study will be performed in Department of Physical Therapy at Federal University of São Carlos, São Carlos/SP, Brazil. One hundred and forty-four patients with chronic neck pain will be randomized into 4 groups: active photobiomodulation therapy with active electrical stimulation, active photobiomodulation therapy, active electrical stimulation, or placebo treatment. They will receive 10 sessions of treatment.

PRIMARY OUTCOME

pain intensity (measured by pain numerical rating scale) posttreatment.

SECONDARY OUTCOMES

pain during movement, neck disability, range of motion, pressure pain threshold, temporal summation, conditioned pain modulation, depressive symptoms, pain catastrophizing, quality of life, analgesic intake, and global perceived effect at posttreatment (10 sessions). Pain intensity and global perceived effect will also be measured after 6 weeks randomization.

DISCUSSION

The findings of this study might clarify the importance of using the photobiomodulation therapy and transcutaneous electrical nerve stimulation for patients with chronic neck pain.

TRIAL REGISTRATION

NCT04020861. https://clinicaltrials.gov/ct2/show/NCT04020861?term=NCT04020861&draw=2&rank=1.

Effects of electroacupuncture frequencies on chronic low back pain in older adults: triple-blind, 12-months protocol for a randomized controlled trial

BACKGROUND

Low back pain (LBP) is the most frequent complaint in clinical practice. Electroacupuncture treatment may be effective; however, the supporting evidence is still limited, especially in older adults.

OBJECTIVE

The current study is a randomized controlled trial that aims to evaluate the clinical efficacy of electroacupuncture in older adults with LBP.

METHODS

A five-arm randomized controlled trial with patients and evaluators blinded to the group allocation. A total of 125 participants with non-specific LBP will be randomly assigned into one of five groups: three electroacupuncture groups (low, high, and alternating frequency); one control group; and one placebo group. The electroacupuncture will be applied twice a week (30 min per session) for five weeks. The primary clinical outcome measure will be pain intensity. The secondary outcomes include: quality of pain; physical functioning; perceived overall effect; emotional functionality; patient satisfaction; and psychosocial factors. Patients will be evaluated before the first session, immediately after the last, and followed up after six and 12 months to check the medium- and long-term effects.

DISCUSSION

Although electroacupuncture is increasingly used to treat LBP, there is no guidance regarding the parameters used, which leads to inconsistent results. Thus, the effect of electroacupuncture (EA) on LBP remains controversial and requires more studies, especially in the older adult population.

CONCLUSION

This is the first randomized controlled trial to evaluate the efficacy of different frequencies of electroacupuncture for treating chronic LBP in older adults. This study will provide evidence on the effectiveness of electroacupuncture as an alternative treatment method for LBP and will entail wider debate about an appropriate acupuncture intervention in this population.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT03802045. Registered on 14 January 2019.

Segmental and extrasegmental hypoalgesic effects of low-frequency pulsed current and modulated kilohertz-frequency currents in healthy subjects: randomized clinical trial

Objective: To compare the segmental and extrasegmental hypoalgesic effects of TENS, IFC and Aussie current on pressure pain threshold (PPT) during and after stimulation in healthy subjects. The second objective was to compare the sensory comfort related to electrical stimulation.Material and Methods: 120 healthy subjects were randomized in TENS, IFC, Aussie current or placebo groups. The electrical stimulation was administered on the forearm. The PPT was measured on the forearm (segmental measure) and on the lower leg (extrasegmental measure) by an algometer at baseline, during and after stimulation of the forearm, and the sensory comfort in relation to electrical stimulation was measured with a visual analogue scale. Statistical analysis was performed using linear mixed models for PPT analysis and one-way ANOVA for sensory comfort analysis.Results: The TENS, IFC and Aussie current increased the segmental and extrasegmental PPTs during application of current compared to the placebo. The PPTs measures and sensory comfort were not significantly different between the TENS, IFC and Aussie current groups.Conclusions: Segmental and extrasegmental hypoalgesic effects may be produced using TENS, IFC or Aussie currents in healthy subjects. Furthermore, all of them presented a similar sensory comfort.

Does the use of interferential current prior to pilates exercises accelerate improvement of chronic nonspecific low back pain?

AIM

To evaluate whether active interferential current (AIC) before pilates exercises improves pain faster than placebo interferential current (PIC) in patients with chronic nonspecific low back pain (CNLBP).

METHODS

A total of 142 patients with CNLBP were treated with AIC or PIC before pilates exercises. Pain intensity was measured daily before and after treatment by Pain Numerical Rating Scale. Statistical analysis was performed using survival analysis for Kaplan-Meier method.

RESULTS

The AIC group presented 30% reduction of pain one session, 50% reduction of pain two sessions and 100% reduction of pain three sessions faster than the PIC group and these improvements were statistically significant (p < 0.05).

CONCLUSION

The AIC before pilates exercises can reduce pain faster than PIC in patients with CNLBP.

Manual therapy applied by general practitioners for nonspecific low back pain: results of the ManRück pilot-study

Background

Nonspecific acute low back pain (LBP) is a common reason for accessing primary care. German guidelines recommend non-steroidal anti-inflammatory drugs and physical activity as evidence-based treatments. Manual Therapy (MT) remains controversial. To increase evidence-based treatment options for general practitioners (GPs), a Pilot-Study was set up to gather information about the required conditions and setting for an RCT.

Methods

The open pilot-study assesses recruitment methods for GPs and patients, timelines, data collection and outcomes of treatment immediately (T0) and 1, 6 and 12 weeks after consultation (T1, T2, T3). Inclusion criteria for GPs were: no experience of MT; for patients: adults between 18 and 50 suffering from LBP for less than 14 days.

Study process: Patients’ control-group (CG) was consecutively recruited first and received standard care. After GPs received a single training session in MT lasting two and a half hours, they consecutively recruited patients with LBP to the intervention group (IG). These patients received add-on MT.

Primary outcomes: (A): timelines and recruitment success, (B): assessment tools and sample size evaluation, (C) clinical findings: pain intensity change from baseline to day 3 and time till (a) analgesic use stopped and (b) 2-point pain reduction on an 11-point scale occurred.

Secondary outcomes: functional capacity, referral rate, use of other therapies, sick leave, patient satisfaction.

Results

14 GPs participated, recruiting 42 patients for the CG and 45 for the IG; 49% (56%) of patients were women. Average baseline pain was 5.98 points, SD: ±2.3 (5.98, SD ±1.8).

For an RCT an extended timeline and enhanced recruitment procedures are required. The assessment tools seem appropriate and provided relevant findings: additional MT led to faster pain reduction. IG showed reduced analgesic use and reduced pain at T1 and improved functional capacity by T2.

Conclusions

Before verifying the encouraging findings that additional MT may lead to faster pain reduction and reduced analgesic use via an RCT, the setting, patients’ structure, and inclusion criteria should be considered more closely.

Trial registration

Number: DRKS00003240 Registry: German Clinical Trials Registry (DRKS) URL: https://www.drks.de/drks_web/. Registration date: 14.11.2011. First patient: March 2012. Funding: the Rut and Klaus Bahlsen Stiftung, Hannover.