The diaphragm: not just a breathing muscle!

We all know the diaphragm is our main breathing muscle, but what about its other important function? The diaphragm plays a key role in postural control and trunk stability, meaning it needs to be functioning well to allow for efficient movement and function of the head and neck, upper limbs and lower limbs. So, pretty much everything! Conversely, restrictions in the peripheral regions can affect the function of the diaphragm. We mentioned in an earlier blog that the diaphragm and the pelvic floor work as a team when it comes to breathing and postural control (you can find that blog here: www.milkwood.net.au/articles). However, the diaphragm is a cornerstone of the body for many reasons.

Firstly, there are nerve signals running back and forth between the diaphragm and the brain via the vagus nerve, which is the main nerve responsible for our “flight or fight” response. Ever found yourself holding your breath when you’re nervous or anxious? Often we instinctively take a deep breath to calm ourselves when we’re feeling uptight – this is a way of reminding our brain that we are not in danger. Chronic stress can seriously affect the function of the diaphragm.

There are also important nerve attachments on the diaphragm that send information to the brain about our posture and position.

The diaphragm muscle has direct connections to the deep abdominal muscles (also essential for trunk stability), as well as many of our major organs: the lungs, heart, liver, oesophagus and large intestine.

When there is a compromise in any part of the system, the brain will always prioritise breathing at the expense of other functions. This can have implications for pelvic floor dysfunction, back pain, neck pain and shoulder girdle issues, amongst other things.

Try this little exercise to check in with your diaphragm function:

1.   Sit or stand in a relaxed upright posture

2.    Place your hands gently at the lower angles of your rib cage, using the space between your thumb and forefinger to wrap around the lower ribs.

3.    Take a deep breath and see if you can feel the ribs expanding in all 4 directions. Your belly should also expand as you breathe in.

4.  If you find your belly feels tight, concentrate on allowing it and your pelvic floor to relax as you inhale.

5.  Notice if one side of the ribs expands more than the other, or of your ribs tend to flare at the front.

If you notice any restrictions or asymmetries in the movement of your ribs, you may have tight muscles, stiff spinal segments or connective tissue restrictions which are limiting your capacity to breathe efficiently. This would be a good time to see a physiotherapist for an assessment, and in the meantime, see if you can spend 5 minutes a day practicing letting go of your belly and pelvic floor as you breathe in.