BACKGROUND: No current standardized set of pelvic floor muscle (PFM) outcome measures have been specifically tested for their applicability in a general female chronic pelvic pain (CPP) population. We aimed to compare PFM function between a randomly selected population-based sample of women with CPP and age-matched pain-free controls using multiple standardized intravaginal examination measures recommended by the International Continence Society.

METHODS: This was a cross-sectional, population-based and controlled study with randomly selected participants among women in Denmark. We reported blinded findings from a set of standardized vaginal PFM examination manoeuvres in 50 female participants (24 with CPP, 26 pain free). A preliminary pilot study ensured the intra- and intertester reliability of the test procedure. PFM outcomes were resting tone, relaxation capacity, strength, surface electromyographic activity and mechanosensitivity. Statistical analyses included unpaired t-tests, Fisher's exact tests and Mann-Whitney tests.

RESULTS: The examination protocol was a reliable and predictable clinical measurement of associated PFM dysfunction in female CPP. Women with CPP had higher PFM resting tone and decreased maximal PFM strength and relaxation capacity compared with pain-free controls. Enhanced PFM pressure-pain sensitivity measured by palpometry during examination was also associated to CPP.

CONCLUSION: This controlled, single-blinded study with randomly selected participants provides new population-based information regarding associated PFM dysfunction in women with CPP using multiple intravaginal examination methods. However, to identify women with CPP who will benefit from a physiotherapeutic specialized intervention, future prospective randomized controlled trials using these reliable and predictive outcomes are needed.