Análise eletromiográfica dos músculos bíceps braquial e reto femoral de portadoras de diabetes do tipo 2 durante contração estática voluntária máxima

Abstract

The investigation of the electrophysiological properties of the neuromuscular system (NS) during the modulation of muscle strength has been studied in several areas. Among the techniques employed for this purpose is surface electromyography (sEMG). In the midst of pathological conditions that can potentially cause changes in the tissue and physiological properties of the SN, and hence the electrophysiological properties during the modulation of force, there is type 2 diabetes mellitus (T2DM). The aim of this study was to investigate, through the values of median frequency (MdF) and power distribution frequency (PDF) of the power spectral density, the electrophysiological properties of sEMG of the biceps brachii muscle (BB) and rectus femoris muscle (RF) of women with T2DM with time since diagnosis <5 years, during static maximum voluntary contraction (SMVC). The study included six patients DM2 (GDM2) and six nondiabetic (GC), sedentary, with similar age and body mass index (BMI). There were no significant differences in the values of SMVC during elbow flexion (21.3 ± 5.0 vs 22.9 ± 3.6 kgf) and knee extension (45.9 ± 14.5 vs 57.6 ± 15.3 kgf) between the GC and GDM2. However, we found significant differences in the values of MdF (125.73 ± 158.17 ± 14.9 Hz vs 24.7 Hz for the EMG signal of BB and 126.02 vs. 148.18 ± 8.1 Hz ± 13.0 Hz for the RF signal, and GDM2 GC, respectively). In investigating the DPF, significant differences in the frequency range between 101 and 110 Hz for sEMG of BB and the bands between 81 and 90 and between 91 Hz and 100 Hz of the sEMG of the RF were found. Although still not have been shown statistically significant for values of strength, significant differences were found for the values of MdF and DPF between the groups evaluated. Such differences may be related in part to the increased duration of action potentials of motor units and involvement in the activation of motor units activated at higher frequency bands.