Women with urinary incontinence (UI) have an increased risk of falling compared to their age-matched peers without UI. Due to the anatomical location of the pelvic floor muscles, they are suspected to contribute to the maintenance of postural stability during everyday activities. Women with UI have weak or dysfunctional pelvic floor muscles. The purpose of this study was to determine if women with UI, specifically stress, urge, and mixed UI, have deficits in postural stability during static tasks and in response to postural perturbations of the support surface.

Methods:​ To measure static stability, 14 women (7 with UI:​ age 51.75 ± 17.85 yrs, height 164.94 ± 5.40 cm, mass 79.38 ± 19.45 kg, number of falls 0.714 ± 1.89, number of pregnancies 1.29 ± 0.76 and 7 controls:​ age 51.71 ± 18.20 yrs, height 163.29 ± 6.64 cm, mass 60.47 ± 8.32 kg, number of falls 0.00 ± 0.00, number of pregnancies 1.29 ± 0.76) stood quietly on a force plate with their eyes open and then eyes closed. These same women had their dynamic stability measured by undergoing perturbations of the force plate in both the toes up and toes down directions. A two-factor MANOVA (group x eyes open/closed) was performed on the following static variables:​ anterioposterior sway, mediolateral sway, length of the path of the center of pressure (COP), sway velocity in quiet stance, and elliptical sway area. Another two-factor MANOVA (group x toes up/down) was performed on the following dynamic variables:​ initial sway, total sway, and sway velocity. The alpha value for all statistical analyses was 0.05.

Results:​ No differences in the static stability variables of anterioposterior sway, mediolateral sway, length of the path of COP, sway velocity in quiet stance, and elliptical sway area were seen between groups. Results of the dynamic stability assessment revealed that the UI group had significantly less initial sway (p=0.006), total sway (p=0.008), and sway velocity (p=0.001) compared to the controls.

Conclusion:​ Women with UI have less COP movement in response to postural perturbations compared to an age and parity-matched control group. Further studies are needed to determine muscular compensations and co-contractions that may be contributing to this response.