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

Int Urogynecol J Pelvic Floor Dysfunct. 2008 Jun;19(6):773-82. doi: 10.1007/s00192-007-0525-3.


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.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Exercise Therapy / methods*
  • Female
  • Humans
  • Isometric Contraction
  • Middle Aged
  • Pregnancy
  • Treatment Outcome
  • Urinary Incontinence, Stress / prevention & control*
  • Urination / physiology