The pelvic floor muscles do not work in isolation. They are a crucial element of our core. The core is actually often mistaken for the abdominal muscles, but it is so much more than that!  

What makes up our core: 

  • The abdominal muscles along with some deep spinal muscles (multifidus) make up the walls of our core 

  • The diaphragm (our main breathing muscle) makes up the lid 

  • The pelvic floor muscles make up the bottom 

Together they create a three-dimensional cylinder found in the middle of our body:   

The co-ordination between the muscles of the core is crucial for their function: 

  • Together they work to stabilise our trunk to allow our arms and legs to work freely and also provide transfer of power across our limbs, e.g., when swinging to hit a ball.  

  • Our abdominal organs live inside the core cylinder and their function can also be affected by the muscles of the core. Any pain, tension or dysfunction can have a knock on effect to the function of the organs and vice versa. 

  • The core cylinder houses and manages our intra-abdominal pressure, which is helpful for defecation, urination, coughing, blowing our nose, postural maintenance and lifting. 

  • Its function can be altered for many different reasons, e.g., abdominal, back or gynaecological surgery, pain (this can be of musculoskeletal nature, i.e., joints or muscles or from any of our organs, e.g., IBS, menstrual related etc.), muscle tension or weakness in any of the core muscles, pregnancy.

The diaphragm (our main breathing muscle) will often dictate the state of the core cylinder seeing as we breathe more than anything else! When everything is working well, our diaphragm lowers when we breathe in and then so can the pelvic floor(1). This reciprocal movement between the diaphragm and pelvic floor is very important to allow our pelvic floor to have full flexibility. It has been shown during exercise and day-to-day movement that the pelvic floor is highly active and variable so therefore it is crucial that our pelvic floor is allowed to move (2, 3, 4, 5, 6). Think of it like a strong trampoline rather than like a cork. To be sure your diaphragm is moving when you are breathing, your abdominal wall should be relaxed and there should be a slight inflation around your waist as you breathe in. 

When our diaphragm is moving well, our intra-abdominal pressure tends to be well regulated. Repetitive and excessive increases in intra-abdominal pressure is one of the mechanisms that can lead to pelvic floor muscle dysfunction.  

References

Talasz et al (2011). Phase-locked parallel movement of diaphragm and pelvic floor during breathing and coughing - a dynamic MRI investigation in healthy females. Int Urogynecol J, 22 (1) 61-8 

Leitener at al (2017). . Evaluation of pelvic floor muscles activity during running in continent & incontinent women: An exploratory study, Neurourol Urodyn, Aug 36 (6) 1570-1576 

Leitner at al (2018). Evaluation of pelvic floor kinematics in continent & incontinent women during running. An exploratory study. Feb 37 (2) 609-618  

Moser et al (2018). Pelvic floor muscle activity during impact activities in continent and incontinent women: a systematic review. Int Urogynecol J 

Moser et al (2019a). Pelvic floor muscle activity during jumps in continent and incontinent women: An exploratory study. Archives of Gynecology & Obstetrics. Published online 10 March 2018 

Moser et al (2019b). Pelvic floor muscle displacement during jumps in continent and incontinent women: An exploratory study. doi.org/10.1002/nau.24161