Interferential Research Articles

Management of Intractable Functional Constipation in Children by Interferential Therapy: Transabdominal or Pelvic Floor.

To compare the effectiveness of pelvic floor interferential (IF) therapy with trans-abdominal IF therapy in children with intractable functional constipation. Information of 64 children (38 boys, 26 girls; mean age: 6.6 ± 2.2) with functional constipation who had been treated with IF therapy were considered for this retrospective study. Group A (n = 32) underwent pelvic IF electrical stimulation + pelvic floor muscle (PFM) exercises while the group B (n = 32) received transabdominal IF therapy + PFM exercises. A complete bowel habit diary, a constipation score questionnaire and a seeable pain scores had been recorded before, after the ending of treatment courses and six months later for children in both groups. Additionally, children had been assessed with a constipation-related quality of life questionnaire before and six months after treatment. The number of patients who compiled the diagnostic criteria for constipation significantly decreased in both groups after treatment, in which 27/32 (84.3%) of patients in each group had no constipation after the ending of therapy courses (P = 1). Fecal soiling episodes reduced in both groups after treatment, this finding was significantly higher in group A than in group B after the ending of therapy courses (P = 0.05) and six months later (P = 0.01). Results of this study showed that using IF therapy both pelvic floor and transabdominal significantly boosts the effects of treatment among patients with functional constipation. Pelvic floor IF therapy is more effective in patients who had concomitant fecal soiling.

The effects of TENS, interferential stimulation, and combined interferential stimulation and pulsed ultrasound on patients with disc herniation-induced radicular pain.

Electrotherapy is part of a physician's toolbox for treating various musculoskeletal conditions, including radicular pain, but the preferred modality is yet unclear. To compare the short-term efficacy of three electrotherapeutic modalities in relieving lumbar disc herniation (LDH)-induced radicular pain. Fourteen patients with LDH-induced radicular pain attended a single session of electrotherapy, which included four 10-min consecutive treatments: transcutaneous electrical nerve stimulation (TENS), interferential (IF) stimulation, a combined treatment with pulsed ultrasound and IF current (CTPI), and a sham control. Treatments were randomized and the straight leg raise (SLR) degree was measured immediately before and after each treatment. Each of the three active modalities significantly improved the SLR score. The most prominent improvement was observed in the CTPI condition, followed by IF and, finally, TENS. The sham stimulation did not affect the SLR scores. A single session with either TENS, IF current or CTPI is sufficient to improve the range of motion and degree of radicular pain associated with LDH. CTPI appears to be the most effective modality of the three, possibly due to greater penetration efficiency of the induced current. The effects of a long-term treatment schedule are yet to be identified.

Interferential Electrical Stimulation Efficacy in the Management of Lower Urinary Tract Dysfunction in Children: A Review of the Literature.

Lower urinary tract dysfunction (LUTD) is the most common problem of the referral children to the pediatric urology clinics. If this condition does not treat early in life, it will be a lifelong problem. During recent decades, electrical stimulation therapy has been expanded and extensively used for the treatment of LUTD in both adults and children. The aim of this review is to suggest clinicians an updated understanding of effects of interferential (IF) electrical stimulation therapy in management of LUTD in children. The search was performed in databases of Medline, PubMed, Google Scholar, ,and Scopus for information about IF electrical stimulation and its application using search words such as " IF electrical stimulation", "transcutaneous IF electrical stimulation" , "IF therapy " , " electrical stimulation", "voiding dysfunction" , " LUTD", " urinary incontinence" and " children". As this review focuses on the answer of this question "Does transcutaneous IF electrical stimulation has effect on management of LUTD in children?" we included the reference list of articles identified by this search strategy and selected those we judged relevant according to our keywords. Clinical trial studies that publishing in English were included. Categorical data were reported as frequencies and percentages. Eleven studies were included in this review. The success rate of IF therapy in these studies has been reported from 61% to 90% of children with LUTD and urinary incontinence. IF electrical stimulation is an effective, safe and reproducible option to manage LUTD and urinary incontinence in children.

Management of Bladder Bowel Dysfunction in Children by Pelvic Floor Interferential Electrical Stimulation and Muscle Exercises: A Randomized Clinical Trial

ObjectiveTo assess efficacy of combined pelvic floor interferential (IF) electrical stimulation and muscle exercises on bladder bowel dysfunction (BBD) in children. Materials and methodsA total of 34 children with BBD (6 boys, 28 girls; mean age 7.4 ± 2.2) were included in this study. Children were evaluated with kidney and bladder ultrasounds, uroflowmetry + electromyography (EMG), and a complete voiding and bowel habit diary before treatment. Exclusion criteria were neuropathic disease, anatomical defects, and mental retardation. Participants were randomly allocated into 2 treatment groups including group A (n = 17) who underwent IF electrical stimulation in addition to pelvic floor muscle (PFM) exercises and group B (n = 17) who received PFM exercises alone. All children were re-evaluated by kidney and bladder ultrasounds, uroflowmetry + EMG and a voiding and bowel habit diary at the end of treatment sessions and 6 months later. ResultsConstipation improved in 14 of 17(82%) and 8 of 17(47%) children in group A and B respectively at the end of treatment sessions (P = .03). Daytime incontinence improved in all children in group A and 2 of 8(25%) children in group B after the treatment (P = .007). Urinary tract infection improved in 8 of 10(80%) and 5 of 13(38.4%) children in group A and B respectively, 6 months after the treatment (P = .02). No significant difference was observed in uroflowmetry measures between 2 groups after the treatment. ConclusionCombination of IF electrical stimulation and PFM exercises is an effective and safe modality for treatment of BBD in children.

Impact of transcutaneous interferential electrical stimulation for management of primary bladder neck dysfunction in children

Several studies have revealed that electrical stimulation is an effective modality for treatment of lower urinary tract (LUT) dysfunction via raising the capacity or compliance of the bladder or maybe by pelvic floor relaxation and reducing detrusor pressure as well. This study aimed to assess the efficacy of transcutaneous interferential (IF) electrical stimulation on LUT symptoms as well as urine flow parameters in children with primary bladder neck dysfunction (PBND). We reviewed the charts of all children with persistent LUT symptoms who underwent IF electrical stimulation between 2010 and 2017. Twenty-three neurologically and anatomically normal children (mean age: 7.7years, range: 5-13) with LUT symptoms were included in this study. Children had different LUT symptoms such as hesitancy, straining, urinary incontinence and constipation with no sufficient response to medical treatment (α -blocker) for at least 6months. IF electrical stimulation was performed for 15 sessions, two times per week. All children were symptomatic and had abnormal urine flow pattern with an electromyographic (EMG) lag time of more than 6s on uroflowmetry with EMG. A voiding chart, uroflowmetry with EMG and kidney and bladder ultrasounds were performed before and after the treatment for all children. Maximum and average urine flow rates, EMG lag time and postvoid residual volume were analyzed. In addition, alpha blocker therapy was continued during IF therapy. Mean maximum and average urine flow rates improved from 14.1 to 7.6-19.7ml/s and 9.5ml/s, respectively, while mean EMG lag time decreased from 11.7 to 5.2s after the treatment (all P<0.05). Also postvoid residual volume decreased significantly from 35.6 to 7.6mlat the end of treatment courses. Pelvic floor EMG lag time, a documented parameter on uroflowmetry with EMG, defined as the time from the start of pelvic floor relaxation during a volitional voiding effort (the first stage of normal voiding) to the start of urine flow. Results showed that IF therapy decreased pelvic floor EMG lag time in children with PBND. In addition, increase in mean maximum and average urine flow rates in our patients indicated that pelvic IF therapy and behavioral modification improved voiding dysfunction in most of the patients and probably decreased bladder neck activity during voiding. Future studies with larger sample size are needed to support this finding. IF therapy appears safe, effective and reproducible in improvement of PBND in children.

Pelvic floor electrical stimulation and muscles training: a combined rehabilitative approach for management of non-neuropathic urinary incontinence in children

PurposeTo assess the efficacy of combined transcutaneous interferential (IF) electrical stimulation and pelvic floor muscle training through biofeedback on non-neuropathic urinary incontinence in children. MethodsThis prospective study comprised of 46 anatomically and neurologically normal children (9 boys, 37 girls; mean age of 8.4 ± 2.2 years old) with non-neuropathic urinary incontinence. All children were evaluated by kidney and bladder ultrasounds, uroflowmetry with electromyography (EMG), a complete voiding diary and a dysfunctional voiding scoring questionnaire at the baseline. Children were randomly allocated into two treatment groups including group A (n = 23) who underwent biofeedback therapy in addition to IF electrical stimulation and group B (n = 23) who received only biofeedback therapy. Re-evaluation was performed 6 months and one year after completion of the treatment sessions. ResultsImprovement of non-neuropathic urinary incontinence was significantly higher in group A in comparison to group B at two follow ups (P < 0.05). Daytime incontinence was improved in 19/23(82%) and 13/23(56.5%) of children in groups A and B respectively after the treatment (P < 0.01). There was no significant difference in uroflowmetry measures between two groups after the treatment. ConclusionsCombination of biofeedback therapy and transcutaneous IF electrical stimulation is a potential effective modality in treating non-neuropathic urinary incontinence in children. Level of EvidenceType of study: Treatment study.Level I: Randomized controlled trials with adequate statistical power to detect differences (narrow confidence intervals) and follow up >80%.

Effects of Interferential Electrical Stimulation Plus Pelvic Floor Muscles Exercises on Functional Constipation in Children: A Randomized Clinical Trial.

Functional constipation is a common condition in children. We assessed the effectiveness of combined interferential (IF) electrical stimulation and pelvic floor muscle (PFM) exercises on functional constipation in children. We conducted a single-center, double-blind randomized clinical trial study during 2014-2017 in Tehran, Iran. Ninety children, aged 5-13 years, who fulfilled Rome III criteria were enrolled and randomly assigned into two treatment groups. Case group (n=45) underwent IF electrical stimulation and PFM exercises, whereas the control group (n=45) received PFM exercises plus sham stimulation. A complete bowel habit diary (with concerning data on the frequency of defecation per week, stool form, and the number of fecal soiling episodes), a constipation score questionnaire, and a visual pain score were recorded before, after the treatment and 6 months later for all participants. In addition, children in both groups were assessed with a constipation-related quality-of-life questionnaire before, after the end of treatment sessions, and 6 months after the treatment. Treatment success was achieved for 88.4% of children in the case group compared with 43.2% of children in the control group after the treatment (P<0.003). The median constipation score was reduced in both groups, with the cases having significantly lower scores after the treatment (4 vs. 8, P<0.000). Stool form normalized in 75.6% of the cases and 45.5% of the controls after the treatment (P<0.01). Our results showed that using IF electrical stimulation as an adjuvant therapy to the medical and rehabilitation programs significantly boosts the effects of treatment among these patients.

A comparative study of transcutaneous interferential electrical stimulation plus behavioral therapy and behavioral therapy alone on constipation in postoperative Hirschsprung disease children

PurposeWe assessed the effectiveness of transcutaneous interferential (IF) electrical stimulation on constipation in postoperative Hirschsprung's disease (HD) patients. MethodsThirty HD children (18 boys and 12 girls) with constipation who had no surgical complication were enrolled and then randomly divided into two treatment groups. The control group underwent only behavioral therapy comprising high fiber diet, hydration, toilet training and pelvic floor muscles exercises while; the IF group underwent behavioral therapy plus IF electrical stimulation. Patients underwent anorectal manometry before and 6months after the treatment. In addition, a complete bowel diary with data on the frequency of defecation per week, stool form and the number of fecal soiling episodes, a constipation score and a visual pain score were obtained from all patients before, after treatment and 6months later. ResultsConstipation symptoms were improved in 10 (66%) and 4 (26.6%) patients in IF and control groups, respectively at 6months of follow up (P<0.03). Frequency of defecation per week significantly increased after the treatment in the IF group compared with control group at the 6months of follow up (5.4±2.1 vs. 3.3±1.8 per week, respectively; P<0.009). In addition, mean pain score was significantly decreased in IF group compared with controls after treatment (P<0.05). ConclusionIF electrical stimulation is an effective adjunct to behavioral therapy to overcome symptoms of constipation in postoperative HD patients.

Efficacy of transcutaneous interferential electrical stimulation in treatment of children with primary nocturnal enuresis: a randomized clinical trial.

Electrical stimulation has been used as an alternative therapy for adult urinary syndromes and for children with constipation. We have evaluated the safety and efficacy of interferential (IF) electrical stimulation in children with nocturnal enuresis (NE). This was a randomized clinical trial in which 54 children (23 girls, 31 boys) aged 6-14 years with primary NE were recruited and randomly divided into two groups. Children in the control group underwent standard urotherapy only (hydration, scheduled voiding, toilet training, diet), whereas children in the IF group (cases) were treated with standard urotherapy + 15 sessions of IF electrical stimulation for 20 min twice per week. An improvement score was calculated to identify relative decrease in wet nights after the treatment for each child. All children were followed for 1 year. Overall, 15/27 (55.5%) and 6/27 (22%) of children in the IF and control groups responded to treatment at the 1-year follow-up (P = 0.01). The mean number of wet nights per week in the control and IF groups decreased from 5.4 ± 2 and 5.7 ± 2 to 3.3 ± 3 and 1.1 ± 2, respectively, at first evaluation (P = 0.003). The mean improvement score in the IF group was significantly higher than that of the control group after 1 year (78 vs. 46%, respectively; P = 0.004). Interferential therapy can be applied as a safe, effective and well-tolerable alternative therapy in the treatment of children with NE.

A new insight into the management of myofascial pain syndrome

Myofascial pain syndrome (MPS) is a musculoskeletal disorder which is characterized by pain, muscle spasms, and muscle tenderness, as well as a limited range of motion, weakness, and rarely, autonomous dysfunction. Management includes exercise programs in particular, and many other invasive and non-invasive therapies, depending on the clinical status of the patient. The main options include medical therapies with analgesics, myorelaxants and antidepressants, hot pack therapy, exercise, stretch and spray therapy, ischemic compression, therapeutic massage, biofeedback, transcutaneous electrical nerve stimulation (TENS), ultrasound (US), interferential (IFA) current, low-energy light amplification by stimulated emission of radiation (LASER), extracorporeal shock wave therapy (ESWT), trigger point injections, dry needling, and acupuncture. There is growing evidence that trigger point injections and dry needling, as well as stretching exercises, are effective alternatives in the management of MPS. Management success is primarily based on the cooperation of the patient and the treating physician and the elimination of predisposing factors.

Transcutaneous interferential electrical stimulation for management of neurogenic bowel dysfunction in children with myelomeningocele

We describe the efficacy of transcutaneous interferential (IF) electrical stimulation on constipation symptoms in children with myelomeningocele (MMC). MMC children (30, comprising of 17 girls and 13 boys), mean age 6.7 ± 2.9, with moderate to severe intractable constipation were enrolled in this study. They were divided into treatment (IF stimulation, 15 children) and control (sham stimulation, 15 children) groups. All children underwent anorectal manometry before and 6 months after IF therapy considering the rectoanal inhibitory reflex and sphincter pressure. Parents were instructed to complete a bowel habit diary by providing data on the number of defecations per week, form of stool and episodes of pain during defecation. According to parents' report a total neurogenic bowel dysfunction score questionnaire was filled before and 6 months after treatment. A 15-course abdominal area IF electrical stimulation was performed for 20 min and three times per week, with low-frequency current in a duration of 250 μs every 6 s. Children were followed up for a minimum period of 6 months. In the treatment group, sphincter pressure and rectoanal inhibitory reflex significantly improved compared with sham stimulation and pretreatment measures (P < .05). In 73% of patients, the characteristics of constipation decreased immediately after IF therapy, while in 53% patients, they persisted for 6 months. Frequency of defecation increased statistically significant from 2.5 ± 1.1 per week before treatment to 4.7 ± 2.3 per week after treatment (P < .001). This pilot study showed that IF therapy is safe, noninvasive, and effective modality to improve constipation symptoms and anorectal manometry parameters in children with history of myelomeningocele.

Editorial Comment

This study evaluates 30 children with myelomeningocele (MMC) (mean age 5.6 ± 2.7 years) and refractory neurogenic detrusor overactivity using pelvic floor electrostimulation with interferential (IF) current. The children had moderate to severe retractable incontinence, detrusor overactivity, and a high maximal detrusor end-fill pressure. Each child required anticholinergic therapy (oxybutynin or baclofen) and clean intermittent catheterization. They were randomly allocated to the treatment (IF stimulation, n = 20) and control (sham stimulation, n = 10) groups with a 2:1 ratio (balanced block randomization). The patients were evaluated with the following: urodynamic studies before treatment, 2 weeks after treatment, and 6 months after treatment, a subjective questionnaire, and measurement of the postvoid residual urine volume. The patients underwent 3 treatment sessions per week for 6 weeks. Immediately after IF therapy, the mean maximal detrusor pressure, postvoid residual urine volume, and detrusor sphincter dyssynergia were significantly reduced in the IF treatment group compared with the sham stimulation group (P < .05). The mean bladder capacity did not increase significantly in either group. Effect of Pelvic Floor Interferential Electrostimulation on Urodynamic Parameters and Incontinency of Children With Myelomeningocele and Detrusor OveractivityUrologyVol. 74Issue 2PreviewTo evaluate safety and efficacy of transcutaneous interferential (IF) electrostimulation on voiding symptoms and urodynamic variables in children with myelomeningocele (MMC)-induced refractory neurogenic detrusor overactivity. Full-Text PDF Editorial CommentUrologyVol. 74Issue 2PreviewWinston Churchill said of democracy that it is the worst form of government except for all the others that have been tried. The same can be said of augmentation cystoplasty (AC); although it is not without its appreciable risks and untoward legacy, it remains the most predictable method of providing patients with spina bifida with social continence and upper tract protection when these cannot be achieved through other means. In the end, these 2 factors must be of paramount concern when evaluating any urinary tract intervention for spina bifida. Full-Text PDF ReplyUrologyVol. 74Issue 2PreviewWe thank the esteemed editors for precise revision of the article and very delicate attention to such fundamental issues with respect to management of this old problem that we share, and we appreciate these concerns; therefore, we address both comments together. There is a growing body of evidence for the efficacy of IF in several functional and organic disturbances (article reference 12).1-3 However, organic bladder insults, such as MMC and multiple sclerosis, have not been investigated sufficiently to date (article references 27 and 28). Full-Text PDF

Reply

We thank the esteemed editors for precise revision of the article and very delicate attention to such fundamental issues with respect to management of this old problem that we share, and we appreciate these concerns; therefore, we address both comments together. There is a growing body of evidence for the efficacy of IF in several functional and organic disturbances (article reference 12). 1 Poitras S. Brosseau L. Evidence-informed management of chronic low back pain with transcutaneous electrical nerve stimulation, interferential current, electrical muscle stimulation, ultrasound, and thermotherapy. Spine J. 2008; 8: 226-233 Abstract Full Text Full Text PDF Scopus (68) Google Scholar , 2 Watson T. The role of electrotherapy in contemporary physiotherapy practice. Man Ther. 2000; 5: 132-141 Abstract Full Text PDF PubMed Scopus (101) Google Scholar , 3 Goats G.C. Interferential current therapy. Br J Sports Med. 1990; 24: 87-92 Crossref PubMed Scopus (97) Google Scholar However, organic bladder insults, such as MMC and multiple sclerosis, have not been investigated sufficiently to date (article references 27 and 28). We believe that an objective measure is required before we consider subjective efficacy of a therapeutic modality; therefore, UDS parameters were the primary outcome in our study. Given the multifactorial nature of patient and parent satisfaction in children with incontinence and spina bifida in general, it seems unreasonable to initially base the success of a modality on these parameters. However, we share the opinion that quality of life improvement and social acceptance is the ultimate goal in treating any patient, and these factors should be addressed and prioritized in the prospect studies as well. Effect of Pelvic Floor Interferential Electrostimulation on Urodynamic Parameters and Incontinency of Children With Myelomeningocele and Detrusor OveractivityUrologyVol. 74Issue 2PreviewTo evaluate safety and efficacy of transcutaneous interferential (IF) electrostimulation on voiding symptoms and urodynamic variables in children with myelomeningocele (MMC)-induced refractory neurogenic detrusor overactivity. Full-Text PDF Editorial CommentUrologyVol. 74Issue 2PreviewThis study evaluates 30 children with myelomeningocele (MMC) (mean age 5.6 ± 2.7 years) and refractory neurogenic detrusor overactivity using pelvic floor electrostimulation with interferential (IF) current. The children had moderate to severe retractable incontinence, detrusor overactivity, and a high maximal detrusor end-fill pressure. Each child required anticholinergic therapy (oxybutynin or baclofen) and clean intermittent catheterization. They were randomly allocated to the treatment (IF stimulation, n = 20) and control (sham stimulation, n = 10) groups with a 2:1 ratio (balanced block randomization). Full-Text PDF Editorial CommentUrologyVol. 74Issue 2PreviewWinston Churchill said of democracy that it is the worst form of government except for all the others that have been tried. The same can be said of augmentation cystoplasty (AC); although it is not without its appreciable risks and untoward legacy, it remains the most predictable method of providing patients with spina bifida with social continence and upper tract protection when these cannot be achieved through other means. In the end, these 2 factors must be of paramount concern when evaluating any urinary tract intervention for spina bifida. Full-Text PDF

Effect of Pelvic Floor Interferential Electrostimulation on Urodynamic Parameters and Incontinency of Children With Myelomeningocele and Detrusor Overactivity

To evaluate safety and efficacy of transcutaneous interferential (IF) electrostimulation on voiding symptoms and urodynamic variables in children with myelomeningocele (MMC)-induced refractory neurogenic detrusor overactivity. Thirty MMC children (18 girls, 12 boys; mean age 5.6 +/- 2.7) with moderate to severe intractable incontinency, detrusor overactivity, and high maximal detrusor end-fill pressure were enrolled and then randomly allocated to treatment (IF stimulation, 20 children) and control (sham stimulation, 10 children) groups. They underwent urodynamic study (UDS) before and after IF and 6 months later, with attention to mean maximal detrusor pressure (MMDP), maximum bladder capacity (MBC), mean detrusor compliance (MDC), postvoiding residue (PVR), and detrusor sphincter dyssynergia (DSD). Daily incontinence score, voiding frequency, and enuresis were also assessed. Eighteen courses of pelvic floor IF electrostimulation for 20 minutes 3 times per week were performed with low-frequency current, duration of 250 microseconds, and repetition time of 6.6 seconds. Of the UDS parameters in the treatment group immediately after IF implication, MMDP, PVR, and DSD significantly improved compared with sham stimulation and pretreatment measures (P < .05). In the treatment group, 78% patients gained continence immediately after IF therapy and 60% had persistent continence for 6 months (P < .05). Immediately after IF treatment, urinary frequency and enuresis also improved (P < .05), with a statistically significant difference between the 2 groups. This study demonstrated that noninvasive IF therapy is effective in improving voiding symptoms including incontinence and UDS parameters of MMC children with neurogenic detrusor overactivity. The clinical beneficial implication of this modality is yet to be determined in larger studies.

Evaluating the benefits of patterned stimulation in the treatment of osteoarthritis of the knee: A multi-center, randomized, single-blind, controlled study with an independent masked evaluator

This study investigated the benefits of the combination of interferential (IF) and patterned muscle stimulation in the treatment of osteoarthritis (OA) of the knee. This was a multi-center, randomized, single-blind, controlled study with an independent observer. The study randomized 116 patients with OA of the knee to a test or control group. The test group received 15 min of IF stimulation followed by 20 min of patterned muscle stimulation. The control group received 35 min of low-current transcutaneous electrical nerve stimulation (TENS). Both groups were treated for 8 weeks. Subjects completed questionnaires at baseline and after 2, 4 and 8 weeks. Primary outcomes included the pain and physical function subscales of the Western Ontario MacMaster (WOMAC) OA Index and Visual Analog Scales (VAS) for pain and quality of life. Compared to the control group, the test group showed reduced pain and increased function. The test group showed a greater decrease in the WOMAC pain subscale (P=0.002), function subscale (P=0.003) and stiffness subscale (P=0.004). More than 70% of the test group, compared to less than 50% of the control group, had at least a 20% reduction in the WOMAC pain subscale. When analyzing only patients who completed the study, the test group had a nominally significant greater decrease in overall pain VAS. No significant between-group differences were observed in incidence of adverse events. In patients with OA of the knee, home-based patterned stimulation appears to be a promising therapy for relieving pain, decreasing stiffness, and increasing function.

The analgesic effects of interferential (IF) current on cold-pressor pain in healthy subjects: a single blind trial of three IF currents against sham IF and control

Interferential (IF) therapy is well documented as a therapeutic medium for pain relief. Despite widespread use by physiotherapists, there remains very limited laboratory or clinical evidence for the analgesic effect of IF.Fifty volunteers were randomly allocated to one of five groups ( n =10): control group (no treatment throughout); IF 100 Hz applied to the ipsilateral limb; IF 100 Hz applied to the contralateral limb; IF 30 Hz applied to the ipsilateral limb; Sham IF applied to the ipsilateral limb. Subjects were given repeated (six) cycles of cold-pressor pain and pain threshold scores were recorded for each cycle and compared using repeated measure ANOVA. Mean pain threshold values for all groups increased with the exception of the control group: where pain threshold values decreased across the cycles. Pain thresholds within IF treatment groups repeatedly increased, but no more than sham IF. IF at 30 Hz and 100 Hz applied to the contralateral limb offered more consistency in the rise in mean values, with the sham group demonstrating more variation in performance. However, statistical analysis failed to show any significant differences for the treatment effects either within groups across repeated cycles (P=0.123) or between the groups across cycles (P=0.552). IF does not significantly alter pain threshold.

The analgesic effects of interferential therapy on cold-induced pain in healthy subjects: a preliminary report

Interferential (IF) therapy is an electrotherapeutic modality used by physiotherapists for the management of a variety of painful conditions. However, the analgesic efficacy of IF remains in doubt and its mechanism of analgesic action is far from understood. This preliminary study examined the effect of IF on cold-induced pain threshold and tolerance in healthy student volunteers. Interferential therapy, when applied to the anterior aspect of the forearm of healthy subjects, significantly elevated ice pain threshold when compared with a control (no treatment) group. These preliminary findings provide objective evidence for the analgesic effects of IF currents.