The Intra-Abdominal Pressure System
The pressure system inside of your abdomen, called the intra-abdominal pressure system, is truly amazing. It is a huge factor in your ability to lift heavy things, breathe comfortably, move through a variety of postures easily, and even hold in urine or a bowel movement, called continence. (I wrote more on this in my post about the connection between your diaphragm and pelvic floor here.)
What makes up this system?
There are a number of parts of your anatomy designed to control, create, and release pressure of the abdomen. Think of it like one of those long, skinny balloons that clowns can make animals out of. Imagine holding that balloon up where the opening to blow into is at the top, and the rest hangs down toward the ground. The bottom end of the inflated balloon is your pelvic floor. The sides of the balloon along the tube are other muscles of your core, like your abdominals and muscles of the back. And at the top, air can come in and out through the skinny opening, which is comparable to your glottis. Pressure in any one part of the balloon will dramatically affect the other parts! You can’t really inflate part of it while not inflating another.
When is this pressure system useful?
A huge value of the pressure system of the abdomen is to be able to create a global contraction of maximal effort. Creating pressure pushing out on all of your big muscle groups helps to “recruit” more of these muscles to turn on at once. Called a valsalva maneuver (when you close your glottis and create a very high abdominal pressure), this would be functional for that extreme example of trying to lift a car off of a child or fighting off an attacker. In training, a valsalva is useful when doing large, Olympic lifts like power cleans or deadlifts.
The other very functional use of the pressure system is to draw air into the lungs. It is the displacement of the diaphragm down into the abdomen that creates the negative pressure in the lungs to force air in for ventilation. Without good control of this movement of the diaphragm, breathing is more shallow and uncoordinated.
What happens when this system isn’t functioning well?
When this system is dysfunctional, it can lead to incontinence, less than optimal movement, and pain. To demonstrate how incontinence can occur, let’s look back on the balloon analogy. If we were to squeeze the middle of that balloon, the pressure would force the bottom of the balloon to stretch and potentially even fail, AKA pop! While our pelvic floor rarely pops open like an upside-down jack-in-the-box or a rupturing balloon, it can temporarily fail by relaxing and releasing all of your typical potty waste (you know the stuff). This is essentially what stress incontinence is, and it is one reason why you should keep your glottis open and breathe through movements to release that pressure.
If you struggle with controlling this pressure system, it can lead to inefficient movement. If you have to exert that push-a-car-off-of-a-child effort with a valsalva every time you stand up from a chair, then you are abusing this technique of muscle recruitment. You should be able to move through your day-to-day without ever having to make a valsalva. If you are not able to move with an open glottis and good breath control, you are constantly straining your pelvic floor and probably over-utilizing a lot of muscles. Paradoxically, while over-utilizing some muscles, you may have a really hard time turning on other muscles in your body. While this technique of holding your breath and creating pressure helps you to recruit a lot of muscle activation to make a big movement, it also limits your ability to selectively recruit other muscles for movements requiring fine control.
How can I train this system?
To train this system, start by being mindful of your breath with easy movements. This is a basic yoga principle: let the breath lead the movement. Try doing something simple like sitting and raising your arms up and down, like they are wings (or the sides of a wine bottle opener… we can all relate to that, I am sure). As you breathe in, raise the arms up, and then breathe out and slowly lower the arms back down. This can be progressed with more challenging exercises. The next time you try to pick something up from the ground (like a child!), inhale as you bend over, and then exhale as you lift up.
By focusing on lifting, moving, and cooperating with the breath, you will notice that it begins to be easier to coordinate this system. It may mean that you can sing and hold a note a lot longer, or that you can go walking/running with a friend and actually talk!