Intraday and interday reliability of pelvic floor muscles electromyography incontinent woman

Aims Vaginal surface electromyography (sEMG) is a tool used for the diagnosis and therapeutic intervention of urinary incontinence. Current sEMG systems differ in regard to electrode arrangement and data reproducibility. The aim of this study was to determine the intrasession, intraday, and interday reliabilities of sEMG parameters using a probe with circumferential electrode-position. Methods The intrasession, intraday, and interday reliabilities of maximum isometric voluntary contractions (MVC) of the pelvic floor muscles were assessed for 19 healthy continent women. Three sEMG parameters that are used to describe muscle activity were verified: maximal EMG (EMG(max)), mean over 500 ms around EMG(max) (EMG(A0.5)), and mean over 2 seconds during MVC plateau (EMG(A2-4)). Relative and absolute reliability parameters were calculated, and the statistical methods described by Bland and Altman were applied to the data. Results We observed substantial reliabilities for all obtained parameters (EMG(max), EMG(A2-4), and EMG(A0.5)) in regard to the intrasession measurements (ICC = 0.93-0.97; CI = 0.86-0.99). Overall, the intraday reliability has been moderate (ICC = 0.64-0.75; CI = 0.27-0.90). EMG(max) (ICC = 0.75; CI = 0.45-0.90) and EMG(A2-4) (ICC = 0.73, CI = 0.42-0.89) were higher than EMG(A0.5) (ICC = 0.64; CI = 0.27-0.85). However, the interday reliability was only fair for EMG(max) (ICC = 0.48; CI = 0.04-0.77) and EMG(A0.5) (ICC = 0.51; CI = 0.07-0.78) but moderate for EMG(A2-4) (ICC = 0.65; CI = 0.28-0.85). Conclusions This intrasession, intraday, and interday reliability results are similar to the results reported in the literature using probes with longitudinally oriented bars. The mean sEMG signal over 2 seconds (EMG(A2-4)) exhibited the highest reliability and is recommended for further studies. The interday reliability might be enhanced by considering the menstruation cycle.