Determination of effective treatment duration of interferential current therapy using electromyography

Effect of premodulated interferential current versus diadynamic current on the management of lateral elbow tendinopathy

Study aim: To compare the effect of premodulated interferential current (PREMOD IFC) and diadynamic current (DD) with exercise training on the management of lateral elbow tendinopathy (LET).

Material and methods: One hundred and four patients with unilateral LET from both genders (55 females and 49 males) were randomly allocated into two groups. Group A received PREMOD IFC in addition to the exercises, and group B received DD with the same exercises. The outcomes were maximum grip strength assessed by the hand dynamometer, the pinch strength assessed by the pinch gauge dynamometer, and pain and functional disability of the forearm assessed by a patient-rated tennis elbow evaluation (PRTEE) questionnaire. All participants received electrical stimulation, consisting of three sessions per week for six weeks.

Results: The mean PRTEE score, and grip strength were significantly improved after six weeks in favour of group A, while there was no significant difference between the two groups in pinch strength. (p < 0.05).

Conclusion: The results revealed that the combination of PREMOD IFC with exercises could improve pain, functional disability, and grip strength compared to DD with exercises in LET patients without a significant difference between the two groups in pinch strength.

The Impact on the Stress-Associated Autonomic Response of Physiotherapy Students Receiving Interferential Current in an Electrotherapy Training Session

Electrical currents are didactic contents widely applied in the training of physiotherapy students, but the treatment is considered a stressful situation for both the patient who receives it and the student who applies it. The aim of this study was to evaluate the stress-associated autonomic response of physiotherapy students receiving interferential current by measuring and analysing heart rate variability. An observational case-control study was conducted. Ninety healthy male volunteers, all physiotherapy degree students, were enrolled while attending laboratory practice during the 2020-2021 academic year. Participants were randomly allocated to a sham electrotherapy group (44 subjects), in which heart rate variability was recorded for 10 min, both at rest and during the application of sham technique on the lower back (10 min), and an electrotherapy group (46 subjects), applying the same procedure with the electrical current flowing. Outcome measures included baseline (seated position) and postintervention (prone position) time domain parameter, diameters of the Poincaré plot 1 and 2, stress score, and sympathetic/parasympathetic ratio. The sham electrotherapy group exhibited significant increases in time domain parameter (p = 0.027) and diameters of the Poincaré plot 1 (p = 0.032), with a small effect size (d ≤ 0.5). The electrotherapy group exhibited significant increases in time domain parameter and diameters of the Poincaré plot 1 and 2 (p < 0.001) and decreases in the stress score and sympathetic/parasympathetic ratio (p < 0.001), with a large effect size (d > 0.8) other than for the time domain parameter (d = 0.42), indicating increased parasympathetic and decreased sympathetic activity. After interventions, there were significant differences between groups in diameters of the Poincaré plot 2 (p < 0.001), stress score (p = 0.01) and sympathetic/parasympathetic ratio (p = 0.003), with moderate effect size (d > 0.5). The application of the interferential current technique produces stress-associated autonomic response characterized by greater parasympathetic activity and decreased sympathetic activity. Further studies are needed to determine possible adverse effects.

Heart Rate Variability Monitoring during Interferential Current Application in the Lower Back Area: A Cross-Sectional Study

Vasovagal reactions may occur occasionally during electrical stimulation using interferential current (IFC). The purpose of this study was to examine variations in autonomic activity during the application of IFC in asymptomatic participants by analysis of their heart rate variability (HRV). Seventy-three male volunteers were randomly assigned to a placebo group (n = 36; HRV was documented for 10 min, both at rest and during a placebo intervention) and an intervention group (n = 37; HRV was documented for 10 min in two conditions labelled as (1) rest and (2) application of IFC technique on the lumbar segment). The diameters of the Poincaré plot (SD1, SD2), stress score (SS), and the ratio between sympathetic and parasympathetic activity (S/PS) were measured. After interventions, differences amongst the placebo group and the IFC group were found in SD2 (p < 0.001), SS (p = 0.01) and S/PS ratio (p = 0.003). The IFC technique was associated with increased parasympathetic modulation, which could induce a vasovagal reaction. Monitorization of adverse reactions should be implemented during the application of IFC technique. HRV indicators might have a part in prevention of vasovagal reactions. Further studies in patients with lumbar pain are needed to explore possible differences in HRV responses due to the presence of chronic pain.

Successful treatment of medial tibial stress syndrome in a collegiate athlete focusing on clinical findings and kinesiological factors contributing to pain

Medial tibial stress syndrome (MTSS) is characterized by the presence of diffuse pain in the posteromedial portion of the medial border of the tibia. Current evidence from the literature has not established an effective treatment and has not been able to demonstrate effectiveness of numerous modalities commonly used to treat MTSS pain.

CASE DESCRIPTION

This report describes an 18-year-old male collegiate soccer player who presented with pain along the distal medial tibial border bilaterally consistent with the diagnosis of medial tibial stress syndrome (MTSS). Treatment focused on correcting clinical and kinesiological findings likely contributing to the patient's condition including fascial mobilization, interferential currents (IFC), strengthening and stretching exercises. After 10 sessions over 10 weeks the patient was able to return to training and competition without pain.

Change of bio-electric interferential currents of acute fatigue and recovery in male sprinters

We studied the muscle fatigue and recovery of thirty male sprinters (aged 18–22 years) using the Frequency Analysis Method (FAM). The interferential currents (ICs) with different thresholds for sensory, motor and pain responses, the maximal voluntary contraction (MVC), and the amplitude of the surface EMG (aEMG, sEMG) were assessed prior to and immediately after an acute explosive fatigue training session, and during one-week recovery. We found that IC increased on average from 32.3 ± 8.9 mA to 37.5 ± 7.5 mA in sensory response at 10 Hz immediately post training (p = 0.004) but decreased at 24-hr post training (p = 0.008) and returned to pre-levels thereafter. Motor and pain response patterns at 10 Hz were similar (motor: p = 0.033 and 0.040; pain: p = 0.022 and 0.019, respectively). The change patterns of ICs were similar to but prior to the changes of sEMG. The agreement between IC assessment and amplitude of sEMG (aEMG)/MVC ratio was good (>95%). The present study suggested that the changes in ICs were prior to the changes in both the aEMG and force during fatigue. These changes may reflect the physiological sensory change due to peripheral fatigue. FAM may be useful as an effective early detection and simple tool for monitoring muscle fatigue during training and recovery in athletes.

The effects of abdominal interferential current therapy on waist circumference and visceral fat distance in obese women

[Purpose] The purpose of this study was to investigate the effects of interferential current therapy on the waist circumference and visceral fat length in obese women. [Subjects and Methods] In this study, we selected 30 patients whose body mass index was over 25 kg/m². The subjects were randomly assigned to receive interferential current therapy three times a week for four weeks (n=15) and transcutaneous electrical nerve stimulation three times a week for four weeks (n=15). Waist circumference was measured in cm using a tape measure with the participant in an upright posture, and the length of visceral fat was measured using a high-resolution, B-mode ultrasound machine. [Results] There was a statistically significant difference between the group of waist circumference and visceral fat length. The change of waist circumference and visceral fat length was larger the experimental group than the control group. [Conclusion] These results can be used as a basis for reducing the risk factors that increase mortality due to diseases and can prevent cardiovascular and other adult diseases caused by obesity.