Forced Expiration and the Pelvic Floor

Diaphragmic breathing has been a staple of pelvic floor treatment for decades. The relationship between the diaphragm and the pelvic floor is one likened to a piston, mechanically speaking, with the pelvic floor (PF) activating both in lift and squeeze during exhalation and increased intra-abdominal pressure.
Have you ever considered how forcefully you cue patients to breathe, and the role this may have on pelvic floor muscle activation? A quasi-experimental repeated measures study conducted by Kitani et al. sought to determine if force of expiration effected automatic activation of the pelvic floor muscles.1
Participants in this study were 26 nulliparous females age 18-35 years, all with normal activation of the pelvic floor muscles. A breathing device was utilized during the study to provide 3 different variations in resistance, measured with spirometry. Cranial displacement of the PF muscles was measured utilizing visualized ultrasound, while squeeze pressure of the PF muscles was measured using a perineometer.
The investigators found that of the three variations in force production during exhalation, a cranial-ventral pelvic floor displacement was found most often during minimum forced expiration during PF training aimed at enhancing displacement in an “optimum and protective direction”.
Clinically, this study reinforces the importance of cuing our patients to exhale gently during PF activation training. My verbal cues include “exhale gently as if you were blowing out birthday candles”, or “exhale gently as if you were trying to blow a feather across a table”. 

1. Kitani L, Apte G, Dedrick G, Sizer P, Brismee J-M.  The Effect of Variations in Forced Expiration Effort on Pelvic Floor Activation in Asymptomatic Women. Journal of Women’s Health Physical Therapy. 2014(38)1:19-27.