Does Transvaginal Neuromuscular Electrical Stimulation Elicit a Pelvic Floor Muscle Contraction? A Pilot Study Using Ultrasonography in Healthy Women

Objective: Neuromuscular electrical stimulation (NMES) of the pelvic floor musculature (PFM) is a popular adjunctive intervention to pelvic floor exercises in those with urinary incontinence. The purpose of this study was to assess if transvaginal NMES (TvNMES) elicits a PFM contraction in supine or standing position and if a contraction can be verified with ultrasound imaging.

Study Design: Repeated design study in which all participants experienced TvNMES in 2 randomly ordered positions of supine and standing.

Methods and Measurement: Six healthy nulliparous women (mean age [SD], 24.8 [2.6] y) were recruited for this pilot study. All gave informed consent and completed a bladder filling protocol to allow for delineation of the bladder from the pelvic floor during ultrasound imaging. Participants used vaginal electrodes and were encouraged to increase intensity to a level of tolerable discomfort. Ultrasound imaging was used to assess the effect on the PFM.

Results: All participants reported the perception of PFM contraction; however, ultrasound imaging confirmed this in only 1 participant in standing position. This participant tolerated higher intensities in the standing and supine positions than the other participants.

Conclusion: Participant report of a PFM contraction was unreliable. Vaginal space restricts the size and orientation of the stimulating surface area; consequently, current density can cause discomfort, which limits the effectiveness of stimulation. On the basis of these findings, physical therapists should assess patients during TvNMES via observation with ultrasound imaging, or visible inspection of the perineum to ensure a PFM contraction is occurring.