Objective: The purpose of the present review article is to analyze the scientific background for the use of vaginal cones in measurement of pelvic floor muscle (PFM) strength and effect on female stress urinary incontinence (SUI).
Material and methods: Literature search is based on articles written in English language compiled from MEDLINE, EMBASE, BIOSIS, and SCISEARCH from 1985 up to 1993. Only one study and one abstract were found dealing with methodology of cones used as measuring devices for PFM strength. Six articles were found evaluating the effect of cones on PFM strength and/or SUI.
Results: The analysis of the literature revealed that there is low correlation between PFM strength (measured by vaginal squeeze pressure and vaginal palpation) and ability to hold the cones in incontinent women. The theoretical basis for strength development using cones can be questioned. The studies evaluating effect on PFM strength and SUI have flaws in design, outcome variables and measurement of PFM strength. Including drop out rates, subjective improvement rates vary between 30-63% in uncontrolled studies.
Conclusion: It is concluded that cones may not be used as objective measuring devices for PFM strength. There is a need for prospective controlled randomized studies applying reliable and valid outcome variables to evaluate the effect of cones in treatment of SUI.