Clarification and confirmation of the Knack maneuver: the effect of volitional pelvic floor muscle contraction to preempt expected stress incontinence

Abstract

The aim of the study was to determine the immediate effect of timing a pelvic muscle contraction with the moment of expected leakage (the Knack maneuver) to preempt cough-related stress incontinence. Women performed a standing stress test using three hard coughs without and then with the Knack maneuver. Volume of urine loss under both conditions was quantified with paper-towel test. Two groups of women were tested: nonpregnant women (n = 64) and pregnant women (n = 29). In nonpregnant women, wetted area decreased from a median (range) of 43.2 (0.2-183.7) cm2 without the Knack maneuver to 6.9 (range of 0 to 183.7 cm2) with it (p < 0.0001); while in pregnant women it decreased from 14.8 (0-169.7) cm2 to 0 (0-96.5) cm2, respectively (p = 0.001). This study confirms the effect from the Knack maneuver as immediate and provides a partial explanation for early response to widely applied pelvic muscle training regimens in women with stress incontinence.

Figures

Figure 1

Degree of leakage volume reduction with use of the Knack maneuver in three different groups of women all with demonstrable stress incontinence: 1a) women over age 59 (data abstracted from Miller, 1998), 1b) nonpregnant women across the age spectrum, and 1c) pregnant women.

Figure 2

Photo of paper towel test showing wetted area corresponding to 3 mL, 1 mL, and 3 drops of water when diameter of the wetted area is circled according to the protocol of 10 seconds after exposure to the liquid. The area outside the line represents absorption occurring after 10 seconds.

Figure 3

Flow chart of leakage reduction with the Knack maneuver in Experiment 1 and Experiment 2