INTRODUCTION AND HYPOTHESIS: The objective of this study is to describe pelvic floor muscle function (PFMF) in relation to age and parity in a general female population and to test whether strength/endurance measurements represent all functions of the pelvic floor musculature.
METHODS: A cross-sectional study was performed on 95% of the women aged 45-85 years from a small Dutch town. Validated questionnaires were used to obtain general information, and vaginal examination to test PFMF was performed on 649 women. Chi-square tests were used to analyse the relation between PFMF versus age and parity. Analysis of variance was used to compare muscle strength and endurance to the other PFMF items.
RESULTS: Response rate to the questionnaire was 62.7% (1,869/2,979). PFM strength and endurance are not positively associated with the effective involuntary muscle contractions during coughing.
CONCLUSIONS: Voluntary muscle contractions decreased with age, but there was no relation with parity. Muscle strength and endurance measurements alone are not sensitive enough to determine PFMF.,
International Urogynecology Journal: and pelvic floor dysfunction
Erasmus MC: University Medical Center Rotterdam

Slieker-ten Hove, M.C.P, Pool-Goudzwaard, A.L, Eijkemans, M.J.C, Steegers-Theunissen, R.P.M, Burger, C.W, & Vierhout, M.E. (2009). Pelvic floor muscle function in a general female population in relation with age and parity and the relation between voluntary and involuntary contractions of the pelvic floor musculature. International Urogynecology Journal: and pelvic floor dysfunction, 20(12), 1497–1504. doi:10.1007/s00192-009-0978-7