Changes in levator ani anatomical configuration following physiotherapy in women with stress urinary incontinence

Abstract

Purpose: We quantified the effect of pelvic floor muscle training on the anatomical configuration of the levator ani using magnetic resonance imaging.

Materials and methods: Five female participants with stress urinary incontinence underwent magnetic resonance imaging before and after participating in a pelvic floor muscle physiotherapy program. Axial T1-weighted images of the levator ani were taken with the participant in a supine position. Source images were then manually segmented and surface modeling was applied to build a 3-dimensional model of the levator ani. Models were then measured to determine the levator ani surface area as well as the encircled volume at rest and during voluntary contraction. The percentage of levator ani retraction and symphysis pubis movement during voluntary contraction before and after physiotherapy were also measured.

Results: After physiotherapy the levator ani surface area at rest was significantly smaller than before physiotherapy, decreasing from 677.11 +/- 45.00 to 620.48 +/- 36.14 mm(2) (p = 0.04). The relative reduction in volume encircled by the levator ani during contraction increased significantly from -11.66 +/- 7.42 to -26.02 +/- 13.52 mm(3) (p = 0.04). Levator ani surface retraction during a voluntary contraction increased significantly from 65.61% +/- 17.07% to 81.70% +/- 16.30% (p = 0.02). Symphysis pubis movement during pelvic floor muscle contraction decreased from 1.45 +/- 1.32 to 0.44 +/- 0.61 mm (p = 0.05).

Conclusions: Findings from this preliminary study indicate that pelvic floor muscle training results in anatomical changes in the levator ani and reduction of pubic movement. These results provide insight into the possible anatomical mechanisms through which physiotherapy enables the pelvic floor muscle to minimize urine leakage.