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

Effects of adding electro-massage to manual therapy for the treatment of individuals with myofascial temporomandibular pain: a randomized controlled trial

OBJECTIVE

To evaluate the effect of the addition of dynamic cervical electrical stimulation (electro-massage, ES) to manual therapy (MT), compared to MT by itself, in individuals with myofascial temporomandibular pain.

METHODOLOGY

A total of 46 participants with bilateral myofascial temporomandibular pain for at least three months were distributed into two groups. Group 1 (n=21) received local MT consisting of soft tissue mobilization and release techniques over the neck and temporomandibular regions. Group 2 (n=25) received an ES procedure in the cervical region combined with the same intervention as group 1. All participants underwent a 2-week protocol. The primary outcomes were pain intensity (Visual Analogue Scale), pressure pain threshold (PPT) at the masseter and upper trapezius muscles (algometer), and pain-free vertical mouth opening (manual gauge). The secondary outcome was active cervical range-of-movement. Measurements were taken at baseline, immediately after intervention, and at a 4-week follow-up.

RESULTS

The ANOVA revealed significant changes over group*time, with better results for group 2 (large effect sizes) regarding pain intensity (p< 0.001; η2>0.14), pressure pain sensitivity and mouth opening (p<0.001; η2>0.14). Similar findings were observed for active cervical range-of-movement in all directions (p<0.001; η2>0.14), except rotation (p≥0.05).

CONCLUSION

Electrical stimulation therapy over the cervical region combined with a MT protocol over the neck and temporomandibular joint shows better clinical benefits than MT by itself in subjects with myofascial temporomandibular pain. Registration code: NCT04098952.

Target engagement of the subgenual anterior cingulate cortex with transcranial temporal interference stimulation in major depressive disorder: a protocol for a randomized sham-controlled trial

Background

Transcranial temporal interference stimulation (tTIS) is a new, emerging neurostimulation technology that utilizes two or more electric fields at specific frequencies to modulate the oscillations of neurons at a desired spatial location in the brain. The physics of tTIS offers the advantage of modulating deep brain structures in a non-invasive fashion and with minimal stimulation of the overlying cortex outside of a selected target. As such, tTIS can be effectively employed in the context of therapeutics for the psychiatric disease of disrupted brain connectivity, such as major depressive disorder (MDD). The subgenual anterior cingulate cortex (sgACC), a key brain center that regulates human emotions and influences negative emotional states, is a plausible target for tTIS in MDD based on reports of its successful neuromodulation with invasive deep brain stimulation.

Methods

This pilot, single-site, double-blind, randomized, sham-controlled interventional clinical trial will be conducted at St. Michael's Hospital - Unity Health Toronto in Toronto, ON, Canada. The primary objective is to demonstrate target engagement of the sgACC with 130 Hz tTIS using resting-state magnetic resonance imaging (MRI) techniques. The secondary objective is to estimate the therapeutic potential of tTIS for MDD by evaluating the change in clinical characteristics of participants and electrophysiological outcomes and providing feasibility and tolerability estimates for a large-scale efficacy trial. Thirty participants (18-65 years) with unipolar, non-psychotic MDD will be recruited and randomized to receive 10 sessions of 130 Hz tTIS or sham stimulation (n = 15 per arm). The trial includes a pre- vs. post-treatment 3T MRI scan of the brain, clinical evaluation, and electroencephalography (EEG) acquisition at rest and during the auditory mismatch negativity (MMN) paradigm.

Discussion

This study is one of the first-ever clinical trials among patients with psychiatric disorders examining the therapeutic potential of repetitive tTIS and its neurobiological mechanisms. Data obtained from this trial will be used to optimize the tTIS approach and design a large-scale efficacy trial. Research in this area has the potential to provide a novel treatment option for individuals with MDD and circuitry-related disorders and may contribute to the process of obtaining regulatory approval for therapeutic applications of tTIS.

Clinical Trial Registration

ClinicalTrials.gov, identifier NCT05295888.

Psychophysiological responses to a multimodal physiotherapy program in fighter pilots with flight-related neck pain: A pilot trial

BACKGROUND

The physical and cognitive demands of combat flying may influence the development and persistence of flight-related neck pain (FRNP). The aim of this pilot study was to analyse the effect of a multimodal physiotherapy program which combined supervised exercise with laser-guided feedback and interferential current therapy on psychophysiological variables in fighter pilots with FRNP.

METHODS

Thirty-one fighter pilots were randomly assigned to two groups (Intervention Group: n = 14; Control Group: n = 17). The intervention consisted of 8 treatment sessions (twice per week) delivered over 4 weeks. The following primary outcomes were assessed: perceived pain intensity (Numeric Pain Rating Scale-NPRS) and Heart Rate Variability (HRV; time-domain, frequency-domain and non-linear variables). A number of secondary outcomes were also assessed: myoelectric activity of the upper trapezius and sternocleidomastoid, pain catastrophizing (Pain Catastrophizing Scale-PCS) and kinesiophobia (TSK-11).

RESULTS

Statistically significant differences (p≤0.05) within and between groups were observed for all outcomes except for frequency domain and non-linear HRV variables. A significant time*group effect (one-way ANOVA) in favour of the intervention group was found for all variables (p<0.001). Effect sizes were large (d≥0.6).

CONCLUSIONS

The use of a multimodal physiotherapy program consisting of supervised exercise with laser-guided feedback and interferential current appears to show clinical benefit in fighter pilots with FRNP.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT05541848.

Efficacy of Core Muscle Exercise Combined with Interferential Therapy in Alleviating Chronic Low Back Pain in High-Performance Fighter Pilots: A Randomized Controlled Trial

BACKGROUND

Chronic low back pain (LBP) related to flight is a prevalent health issue in military aviation, impacting pilots. The objective of this investigation was to ascertain if the application of core muscle training in conjunction with interferential current (IFC) therapy results in a reduction in pain severity and associated disability, consequently enhancing core muscle functionality in Chinese Air Force high-performance fighter pilots experiencing chronic LBP.

METHODS

Fifty-three fighter pilots with chronic LBP were randomized into 3 groups: a core muscle exercise combined with IFC group (CG, n = 19), a core muscle exercise group (EG, n = 19), and an IFC group (IG, n = 15). The three groups underwent therapeutic intervention 5 times a week for 12 weeks. The primary outcomes were pain intensity, Oswestry Disability Index (ODI) score and SF-12 health-related quality of life (PCS and MCS) score. Secondary outcomes included evaluations of trunk muscle strength, endurance, and range of motion (ROM) during medial/lateral rotation to assess muscle functionality. Measurements were obtained both before and after the implementation of the intervention therapy.

RESULTS

After 12 weeks of intervention therapy, all the health condition parameters significantly improved among the three groups. However, the CG had a significant improvement in pain intensity compared to the EG (MD = - 0.84 scores; 95% CI = - 1.54 to - 0.15; p = 0.013) and the IG (MD = - 1.22 scores; 95% CI = - 1.96 to - 0.48; p = 0.000). Additionally, the CG led to greater conservation of ODI and improved SF-12 PCS scores than did the IG (p < 0.05). Finally, compared with those at baseline, the core muscle function parameters in the CG and EG improved significantly at the end of the study, but no statistically significant differences were observed between the two groups (p > 0.05).

CONCLUSION

Among participants with chronic LBP, three intervention therapies appear effective in reducing pain, diminishing disability, and enhancing quality of life. Also, combined therapy significantly improved pain and disability compared to the other two monotherapies; moreover, combined therapy and core muscle exercise provided similar benefits in terms of core muscle function after 12 weeks of intervention therapy.

Does interferential current provide additional benefit to orthopedic rehabilitation for the patients with proximal humeral fractures? A randomized controlled study

BACKGROUND

Approximately 80% of all proximal humeral fractures (PHFs) are non-displaced or minimally displaced fractures, which can be treated with conservative treatment. This study investigated the effect of interferential current (IFC) added to orthopedic rehabilitation on shoulder function, pain, and disability in patients with PHF.

METHODS

This study was a prospective, double-blind, randomized, placebo-controlled conducted in physical medicine and rehabilitation outpatient clinic. Thirty-five patients were randomly separated into the IFC group (n = 18) and the sham group (n = 17). The orthopedic rehabilitation program was applied to all patients by the same physiotherapist three times a week for four weeks. Patients in the IFC group received the intervention for 20 minutes 3 times a week before the exercise. The same pads were performed for the sham group, but no electrical stimulation was applied. Constant-Murley score (CMS) for shoulder function, visual analog scale (VAS) activity pain, disabilities of the arm, shoulder, and hand (DASH) score, and paracetamol intake were recorded post-treatment, at 6 weeks and 18 weeks post-treatment.

RESULTS

The demographic and fracture characteristics were not different between the groups. Significant differences were observed in the IFC and sham group in intragroup comparisons of total CMS, VAS activity pain, DASH score, and paracetamol intake over time (p < 0.001). Significant improvement over time was valid for all pairwise comparisons in both groups. However, no significant differences were detected between the IFC and sham group.

CONCLUSION

IFC added to orthopedic rehabilitation could not appear to be an electrotherapy modality that could potentially benefit shoulder function and disability in patients with PHF.

ANF therapy® for pain management, feasibility, satisfaction, perceived symptom reduction and side effects: a real-world multisite observational study

[Purpose] Non-invasive and drug-free interventions for pain are being developed. One of them is ANF (which stands for "Amino Neuro Frequency") Therapy®, which consists in the application of carbonized metal devices on a patient's skin. We aimed to: 1) test perceived changes in pain intensity after ANF application, 2) record frequency and severity of side effects, 3) assess clinician and patient satisfaction, 4) explore effects on swelling and range of motion (ROM). [Participants and Methods] In this real-world multisite observational study, N=113 physical therapists in 45 countries, applied ANF to N=1,054 patients (Mage=45.2, 56.2% female) with pain complaints. Demographic data, pain intensity (NRS-11), effects of ANF on swelling and ROM, clinician and patient satisfaction and side effects were collected. [Results] Main pain locations were: low back (14.9%), knee (12.4%), neck (10%), and shoulder (9.6%). Pre-treatment pain intensity was high (Mean=7.6, SD=1.9). It significantly decreased post-treatment (Mean=3.1, SD=2.0), t(1053)=7.25, with a large effect size (Cohen's d=2.2). Swelling decreased and ROM increased. Average satisfaction with ANF was 92/100. Patients often experienced mild side effects (42.3%): dry mouth, headache and fatigue. [Conclusion] Results show large effect sizes, high satisfaction, and mild and short-term side effects. This is very promising but should be interpreted with caution considering the study limitations.

Short term effects of a novel combined approach compared with physical therapy alone among older patients with temporomandibular degenerative joint disease: a prospective cohort study

BACKGROUND

There is a lack of consensus regarding the best treatment option, including physical exercise, available for temporomandibular degenerative joint disease (DJD) that affect the older patients. Herein, we aimed to study and compare the efficacy of a combined approach using injection and home physical exercise with physical therapy alone as well as explored an optimal treatment strategy for older patients with DJD.

METHODS

We included 213 older patients with DJD treated at our medical centre from June 2020 to June 2021, 64 of whom were selected for analysis. Of these 64 patients, 32 received injections combined with home physical exercise, and the other 32 received physical therapy alone. Propensity score matching was used to ensure that the two groups did not differ significantly in categorical and continuous variables. Measurements included pain intensity, maximum mouth opening, joint crepitus, jaw functional limitation scale (JFLS) scores, treatment times, and treatment durations. Improvement in each measurement was compared between the two groups 2, 4, and 12 weeks after the treatment commenced, as were the final treatment times and durations.

RESULTS

Pain intensity, maximum mouth opening, and JFLS scores in the two groups improved 2, 4, and 12 weeks after treatment (all p < 0.05). The crepitus ratio improved significantly only in the combined treatment group after 12 weeks. Compared with the physical therapy group, pain while opening the mouth improved after 2, 4, and 12 weeks in the combined treatment group. Furthermore, 2 weeks after treatment, the physical therapy group showed significant improvement in maximal mouth opening compared with the combined treatment group. No significant between-group differences were observed regarding improvement in joint crepitus and JFLS scores at each observation point. The combined treatment group had a significantly lower number of visits than the physical therapy group; however, the treatment duration was longer.

CONCLUSION

Compared with physical therapy, pain while opening the mouth is significantly improved by the combined treatment within 12 weeks, and the number of required visits is fewer. Physical therapy improves the patients' mouth-opening capabilities in a short time (2 weeks), and the treatment cycle is short.

Analysis of Spin in the Reporting of Studies on Electroanalgesia for Musculoskeletal Pain

OBJECTIVE

The purpose of this study was to analyze the quality of reporting and presence of spin in abstracts of randomized clinical trials (RCTs) on the use of electroanalgesia for musculoskeletal pain.

METHODS

The Physiotherapy Evidence Database (PEDro) was searched from 2010 to June 2021. Inclusion criteria were RCTs using electroanalgesia in individuals with musculoskeletal pain, written in any language, comparing 2 or more groups, and with pain as 1 of the outcomes. Two blinded, independent, and calibrated evaluators (Gwet's AC1 agreement analysis) performed eligibility and data extraction. General characteristics, report of outcomes, quality of reporting (Consolidated Standards of Reporting Trials for Abstracts [CONSORT-A]), and spin analysis (7-item spin checklist and spin analysis per section) were extracted from abstracts.

RESULTS

Of 989 studies selected, 173 abstracts were analyzed after screening and eligibility criteria. Mean risk of bias on the PEDro scale was 6.02 ± 1.6 points. Most abstracts did not report significant differences for primary (51.4%) and secondary (63%) outcomes. Mean quality of reporting was 5.10 ± 2.4 points in the CONSORT-A, and spin was 2.97 ± 1.7. Abstracts had at least 1 type of spin (93%), and the conclusion presented the greatest number of spin types. More than 50% of abstracts recommended an intervention without significant differences between groups.

CONCLUSION

This study found that the majority of RCT abstracts on electroanalgesia for musculoskeletal conditions in our sample had a moderate to high risk of bias, incomplete or missing information, and some type of spin. We recommend that health care providers who use electroanalgesia and the scientific community be aware of spin in published studies.

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.