What Is Intra-Abdominal Pressure And Why Does It Matter?
Intra-abdominal (IAP) pressure is defined as the steady-state pressure concealed within the abdominal cavity and resulting from the interaction between the abdominal wall and viscera; IAP oscillates according to respiratory phase and abdominal wall resistance.
How do we educate people who have lost the capacity to appropriately use intra-abdominal pressure? Think about the following statement: The appropriate amount of stiffness for the anticipated activity. What does this best describe? Stability? Core Control? Powerhouse? All of these things?
The answer is all of them. Whether we are talking about stability, the powerhouse, or core control, we should be talking about the same concept. That is, does someone have the right amount of support for the anticipated load or activity? I intentionally use the word anticipated. The brain is using information from past experiences to determine the best approach. This enables us without thinking to know how much stiffness to create in preparation for picking up a jug of milk versus a bag of dried leaves for example.
Joseph Pilates implied that the powerhouse is where things start. What kind of tools do we as movement practitioners have to facilitate the appropriate amount of stiffness for the anticipated load? When asked how they would rank the greatest influencers of intra-abdominal pressure, our #PilatesHour webinar attendees answered as follows:
A lot of people think it is about muscle control or abdominal strength. This is not the case. When we talk about the abdominal wall and intra-abdominal pressure with our clients, we often confuse them. This is because intra-abdominal pressure involves much more than just the abdominal wall. Intra-abdominal pressure is the stiffness inside the trunk, particularly in between the chest and the pelvic floor. It is this stiffness that is necessary to control the amount of movement based on the load.
The Power Of Breath
Breath is a powerful influencer of intra-abdominal pressure. The diaphragm is in fact one of the primary muscles and controllers of intra-abdominal pressure. Some people do not utilize the breath or the diaphragm efficiently or as part of dynamic control. This provides a terrific opportunity for Pilates instructors to affect IAP simply through training efficient and supportive breath patterns.
The appropriate amount of stiffness is going to be determined by the activity and facilitated by proper alignment. For example, holding your breath in and of itself will create stiffness, but does it create the appropriate amount of stiffness? Is this a stiffness or support that can be maintained for a period of time? Proper alignment and practice lead to efficient and successful movement that seldom has to do with core strength.
Most of our bodies are given the appropriate amount of strength to be able to handle the movements we choose to participate in. That does not mean that tomorrow, with my body in its current condition, I can go out and perform a 400-pound deadlift if I chose to. I am not conditioned for this activity, nor do I have a need to lift 400 pounds.
However, if I were training to perform that specific loaded movement, my body would naturally start gaining strength by steadily increasing the deadlift weight. Tissue adaptation would happen, meaning that my abdominal wall, my back muscles, and my pelvic floor would all start to change based on the demand that I would be making on those tissues.
This leads to the question, How much control, mobility, or stiffness is necessary to accomplish the task at hand?
Let’s say the box in this photo weighs 40 pounds. What parts of his body must recruit and create stiffness to keep him from falling? What if the box were 100 pounds, vs 15 pounds. How would that change the situation?
When we look at the dynamic movement of kicking a ball, what are they doing and what muscles must be turned on for the person in the photo to be able to kick the ball? Which fascial trains or slings are being activated or tensioned to be able to have the appropriate amount of control of the trunk so that their leg and body can accelerate the foot through space and kick the ball down the field?
How can we support clients in improving the efficiency of their intra-abdominal pressure?
- Help them find their optimal alignment
- Help them find efficient breath patterns within their optimal alignment
- Progressively load them, working always within ranges where they can maintain the above
- Work through the above points to help them perform the activities in which they want to participate
With this basic introduction to intra-abdominal pressure, we see that it is more about alignment, breath, and load than focused abdominal work. I encourage you to try facilitating the above points with your clients and see how their quality of movement and integration with activity improve.
Brent Anderson, PhD, PT, OCS, NCPT is the President and Founder of Polestar Pilates International. Brent is a licensed physical therapist and orthopedic certified specialist with more than 22 years of experience. Based on his extensive background in rehabilitation and movement science, Brent elaborates on Joseph Pilates’ mind-body work through the Polestar curriculum by developing tools for critical reasoning and applying supportive scientific research. He also infuses the integral role of psychology and energy systems on motor control and motor learning.
Brent hosts our weekly webinar #PilatesHour featuring special guests from the movement science field and Polestar community. Watch episode 82 “The Science And Myth of Intra-Abdominal Pressure” here.
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