**Abstract**

The aim of this work was to analyse pelvic floor muscle activity by intravaginal perineometry. We focused on the increase caused by phasic muscular activity, which, on a short term basis, rises above the basal tonic activity. The functional relationships to postural and respiratory function have been confirmed by only a few studies. Therefore, we monitored this functional connection. We confirmed a statistically significant increase in pelvic floor muscle activity at deep breathing compared to calm breathing (in other words at different breathing intensity) in the same position (lying, standing). Our measurements also showed that the phasic activity of pelvic floor muscles in deep breathing is statistically significantly higher than activity after a minute-long run on the treadmill. Cough is a specific situation, whose short-term increase in pelvic floor muscle activity clearly exceeds all other monitored situations.

**Keywords:** pelvic floor muscle, breathing, perineometer, body position
