Electromyography Analysis of Upper Trapezius Relaxation Induced by Interferential Current in Subjects with Neck Discomfort

Purpose: To evaluate the muscular relaxation of the upper trapezius induced by interferential current (IFC) application during rest and functional activities using surface electromyography registration (EMG). Method: We evaluated the “root mean square” value (RMS) of the upper trapezius during rest and functional activities in subjects with neck discomfort before and after IFC applications. Thirty female participated in the study, mean age of 23.0 (±4.0) years and a body mass of 22.1 (±2.5) kg/m2. The subjects received three IFC applications over a 5-day period, with a frequency of 4.000 Hz, an amplitude modulated frequency (AMF) of 75 Hz, a frequency variation (ΔF) of 35 Hz, a slope of 1/1, a sensorial level intensity, and an application time of 30 minutes per session in the upper trapezius. Results: Repeated measures analysis of variance demonstrated significant bilateral decrease (p<0.001) of mean RMS value of the upper trapezius in the final evaluation in relation to initial evaluations. This suggests that IFC can promote a muscle-relaxing effect after a few applications such as during rest as well as during functional activities. Electromyography Analysis of Upper Trapezius Relaxation Induced by Interferential Current in Subjects with Neck Discomfort Ana Paula Moura Campos Carvalho e Silva (PT)1 Adriano Alexandre Acedo (PT)2 Ana Carolina Luduvice Antunes (PT)2 Marcio Guimarães dos Santos (PT)1 Thiago Yukio Fukuda (PT, PhD)3 Adilson Apolinário (PT)2 Patrícia Horta Andrade Finotti (MSc)2 1 Irmandade da Santa Casa de Misericórdia de São Paulo, Physical Therapy Sector (ISCMSP), São Paulo, Brazil 2 Centro Universitário São Camilo, Physical Therapy Sector (CUSC), São Paulo, Brazil 3 Irmandade Santa Casa de Misericórdia de São Paulo, Physical Therapy Sector (ISCMSP); Centro Universitário São Camilo (CUSC) São Paulo, Brazil