To analyze the proportions of improvement after the intervention in relation to primary outcome we will consider the proportion of women with values equal or above 2 using the modified oxford grading scale. The sample size calculation will be done based in a pilot study after the study initiate (after registration) considering we found no data from a RCT investigating exactly the same intervention. The study of Vasconcelos et al. (2017) that investigated a similar intervention in the same population performed a sample size calculation using a test of differences between proportions and Fisher's exact test based in the proportion of change in the group receiving electrical stimulation ( 0.35 point) and in the control group (CG) (0.13 point). Considering a significance level of 5% and 80% test power, in the comparison between the intervention group (IG) and control group (CG), the minimum number indicated was 61 participants per group; however as the intervention was not exactly the same and the control group received instructions to perform home training we intend to do this calculation again based in a pilot sample after the study initiate (after registration).