Urethral Responses to Position Changes

Abstract

Urethral closure pressure will be affected by position changes in both the normal, continent woman and the woman suffering from genuine stress incontinence. Typically, as shown in Fig. 18.1, the continent woman will respond to the increasing stress of a more upright position by increasing skeletal muscle activity within the wall of the urethra as well as within the pelvic floor musculature to lead to an increase in urethral closure pressure. In Fig. 18.1, this is demonstrated by an increased urethral pressure and urethral closure pressure in the sitting position when compared to the supine position. This recruitment of skeletal muscle is a normal compensating response reflected in the periurethral EMG activity.