Comparison of combined therapy with ultrasound-associated interferential current in healthy subjects

Abstract

BACKGROUND AND OBJECTIVES: Although used in the therapeutic field, there is a shortage of studies that evaluate combined therapy or the association of electrical currents with therapeutic ultrasound, the present study aimed to compare the two forms in healthy individuals, analyzing the pain, number of accommodations and current intensity. METHODS: Thirty healthy volunteers took turns for three weeks in three groups. Nociception was evaluated by means of pressure and thermal stimuli in the lumbar spine and respective dermatomes. Then, the volunteer’s dominant foot was submerged in cold water to evaluate the threshold of pain and its intensity. Shortly after, electroanalgesia (combined therapy, only current association with ultrasound, or placebo) was applied for 15 minutes. The application of the bipolar interferential current used a frequency of 4kHz, and amplitude modulation frequency of 100Hz, with one electrode on L3 and the other on S1. When combined therapy was used, the ultrasound head (1MHz) played the role of the electrode positioned over the L5-S1 region, in continuous form, at a dose of 0.4W/cm2. The intensity of the initial and final current was evaluated, as well as the number of accommodations. RESULTS: There was no significant difference between the pain thresholds of pressure and cold, but the combined therapy required more current intensity despite having a smaller number of accommodations. CONCLUSION: None of the therapies produced a difference in pain thresholds, but the combined therapy had fewer accommodations.