Effect of Vaginal Palpation on Voluntary Pelvic Floor Muscle Performance During Early Motor Learning in Women with Stress Urinary Incontinence (SUI): A Randomized Controlled Trial

INTRODUCTION AND HYPOTHESIS: Seventy percent of women with pelvic floor muscle (PFM) dysfunction are unable to contract these muscles correctly. Instruction to contract properly is essential for effective PFM training (PFMT). The study aimed to compare two groups of women with stress urinary incontinence (SUI): one group that received verbal instructions and body awareness techniques, and a second group that also incorporated vaginal palpation. METHODS: Randomized control trial with two groups; 176 women with SUI were included (n = 88 in each group). The experimental group received vaginal palpation, body awareness techniques, and verbal instructions on PFM anatomy and function. The control group received similar body awareness techniques and verbal instructions. The primary outcome was the number of PFM fast voluntary contractions. Secondary outcomes included PFM performance (Oxford scale) and endurance, simultaneous external muscles groups (abdominal, gluteal, hip adductor) contractions, and self-efficacy and expectations for the results. Outcomes were measured after a 4-week intervention. Per-protocol (PP) and intention-to-treat (ITT) analysis were performed. P value ≤ 0.05 was considered statistically significant. RESULTS: Both interventions groups increased the number of fast voluntary contractions [PP OR -0.1 (95% CI -0.8 to 0.5), p = 0.717]; (ITT p = 0.804). PFM voluntary contraction (p = 0.121) and muscle endurance (p = 0.757) were similar between groups. Reduction in simultaneous contractions of gluteus maximus was more pronounced in the experimental group compared to the control group (8.9% vs. 26.9% of patients, respectively; p = 0.003). Both groups showed similar ability to perform PFM contractions and similar self-perception of results, motivation, and confidence of PFM exercises. CONCLUSIONS: Vaginal palpation provided limited additional benefit in improving voluntary PFM performance in women able to perform an initial voluntary contraction but was associated with improved contraction selectivity.