KEY WORDS Pelvic floor Posture

Vaginal closure force Objective: This study was undertaken to quantify resting vaginal closure force (VCFREST), maximum vaginal closure force (VCFMAX), and augmentation of vaginal closure force augmentation (VCFAUG) when supine and standing and to determine whether the change in intra-abdominal pressure associated with change in posture accounts for differences in VCF. Study design: Thirty-nine asymptomatic, continent women were recruited to determine, when supine and standing, the vaginal closure force (eg, the force closing the vagina in the mid-sagittal plane) and bladder pressures at rest and at maximal voluntary contraction. VCF was measured with an instrumented vaginal speculum and bladder pressure was determined with a microtip catheter. VCFREST was the resting pelvic floor tone, and VCFMAX was the peak pelvic floor force during a maximal voluntary contraction. VCFAUG was the difference between VCFMAX and VCFREST. T tests and Pearson correlation coefficients were used for analysis. Results: VCFREST when supine was 3.6 G 0.8 N and when standing was 6.9 G 1.5 Nda 92% difference (P!.001). The VCFMAX when supine was 7.5G 2.9 N and when standing was 10.1G 2.4 Nda 35 % difference (P!.001). Bladder pressure when supine (10.5 G 4.7 cm H2O) wa