Confiabilidade intra e interavaliador da análise eletromiográfica dos músculos do assoalho pélvico: estudo observacional transversal

Abstract

Introduction: Pelvic floor muscles (PFM) require detailed clinical evaluation with reliable tools. Surface electromyography (EMGs) is one of the established methods to assess the PFM function, but it has different protocols for evaluating and analyzing data. Therefore, this study aimed to investigate the intrarater and interrater reliability of the determination by visual inspection of the EMG signal during maximum voluntary contraction (MVC) of female PFM. Methods: This is a cross-sectional observational study with secondary data, previously collected. Records of 3 PFM MVC that had 5 seconds (s) each, separated by 60s intervals, were analyzed. Two independent raters visually determined the onset and offset of each MVC. The agreement between raters on the quality of the signals was analyzed both qualitatively (visual inspection) and quantitatively (signal-to-noise ratio, SNR). The intrarater and interrater reliability was measured taking into account the values ​​of the integral (time domain) and median frequency (frequency domain) of the MVC was analyzed using intraclass correlation coefficient models (ICC 2,1 , ICC 2,3 ) and repeated measures analysis of variance. Results: Data from 58 women (mean age of 54.68 years) were analyzed. Of the total, 22 (37.9%) were considered of high quality by both raters and the SNR ranged 34.3–22.2 decibels (dB). The agreement of qualitative visual evaluation of the sEMG signal was fair (Cohen’s κ=0.306 [0.148; 0.463]). Intrarater and interrater reliability were excellent for the average of the three MVC, both for integral (ICC 2,3 =0.884 [0.821; 0.925]; ω 2 =-0.006, p=0.558) and MDF (ICC 2,3 =0.998 [0.998; 0.999]; ω 2 =-0.009, p=0.992). Conclusion: To date, this is the first study to evaluate intrarater and interrater reliability by identifying the PFM contraction through visual inspection in an sEMG software commonly used in the clinical practice of physiotherapists specialized in pelvic floor dysfunction. Qualitative visual analysis of the sEMG signal presents fair interrater agreement and reflects the SNR. Visual determination of the onset and offset of the MVC of PFM using the standard interface of the sEMG software has excellent reliability for determination of muscle activation variables.