Normative values for Glazer Protocol in the evaluation of pelvic floor muscle bioelectrical activity

The aim of the study was to evaluate pelvic floor muscle bioelectrical activity in healthy, young, and nulliparous women, and to present normative values for all phases and parameters measured with the Glazer Protocol. In this study, 96 healthy, young, nulliparous women (age 22–27 years; 168.6 ± 5.1 cm; 57.1 ± 11.8 kg) were tested. The bioelectrical activity of the pelvic floor muscles was collected using an endovaginal electrode with the Glazer Protocol, which included the following series of muscles contractions and relaxations: pre-baseline rest, phasic contractions, tonic contractions, isometric contractions for muscle endurance evaluation, and post-baseline rest. The following normative values of the bioelectrical signal for all phases of the Glazer Protocol were calculated: mean, minimal, and maximal values, 95% confidence interval, standard deviation, 95% standard deviation confidence interval, variance, coefficient of variation, and standard error of measurement. Average Mean Amplitude (μV) was as follows: pre-baseline rest (6.26 ± 3.33 μV), phasic contractions (49.76 ± 26.44 μV), tonic contractions (37.05 ± 25.99 μV), endurance contraction (16.10 ± 6.68 μV), and post-baseline rest (6.93 ± 3.99 μV). This study was the first in which normative values for all phases of the Glazer Protocol were reported. This protocol is very often used in electromyography devices as a tool for pelvic floor muscle assessment. Due to the fact that the interpretation of the pelvic floor muscle evaluation is complex and difficult, the authors believe that the normative values proposed in this study allow for comprehensive interpretation of this test (both qualitatively and quantitatively) and provide a reference point for parameters measured in women with different pelvic floor dysfunctions.