Is there evidence for pelvic floor muscle relaxation training in nonneurogenic female bladder outlet obstruction?-A narrative review

IntroductionFunctional bladder outlet obstruction (BOO) in women is postulated to be caused by pelvic floor muscle (PFM) dyssynergia or increased tone. The aim of the present review was to investigate the effect of PFM relaxation training on PFM tone and female BOO symptoms.Materials and MethodsThis was a narrative review using an open search strategy on PubMed with the search terms "Bladder outlet obstruction" AND "female" AND ("pelvic floor muscles" OR "Kegel"). The risk of bias of the randomized controlled trials (RCTs) was scored with the Physiotherapy Evidence Database (PEDro) scale (0-10).ResultsOnly three RCTs were found. All three RCTs compared different types of exercise, and no trial compared relaxation training with no or sham treatment. None of the trials reported the effect between groups on the reduction of PFM tone. There was a tendency toward positive effect of PFM relaxation training to improve BOO symptoms in women. PEDro score varied between 4 and 7. Few studies yielded information on the immediate effect of any type of PFM relaxation technique on PFM tone.ConclusionFew RCTs have been conducted on the effect of PFM relaxation training on PFM tone and functional female BOO symptoms. There is an urgent need for RCTs with high methodological and interventional quality in addition to basic research on mechanisms of different relaxation techniques on PFM activity.