Strength and endurance of the pelvic floor muscles in continent women: an observational study

Objectives: To describe the maximal strength and endurance of the pelvic floor muscles in a cohort of women with no history of incontinence; and to determine the effect of age, parity, hormonal status, previous gynaecological surgery and regular performance of pelvic floor muscle exercises on the strength and endurance of these muscles.

Design: Preliminary cross-sectional observational study.

Setting: Faculty of Health Sciences, University of Sydney, Australia.

Participants: Twenty-eight women aged 19 to 58 years, 16 of whom were under 40 years of age. Participants were excluded if they had a history of incontinence or were currently menstruating.

Primary outcome measures: Pelvic floor muscle strength assessed using a perineometer, and pelvic floor muscle endurance above 60% of maximal voluntary contraction.

Secondary outcome measures: The effect of age, parity, hormonal status, previous gynaecological surgery and regular performance of pelvic floor muscle exercises on the strength and endurance of these muscles.

Results: Maximum strength of the pelvic floor muscles was not correlated with endurance (r=0.21, P=0.290) or age (r=-0.31, P=0.107); however, it was influenced by parity (r=-0.44, P=0.020). Endurance was significantly and positively correlated with age (r=0.38, P=0.048).

Conclusions: This study provides preliminary data that age and parity may be important factors in pelvic floor muscle performance in women who are continent. A larger study that considers the variability associated with these variables will provide useful guidelines for prescription of exercise.