The “Pop Can” Core (understanding core function)

The core is arguably the most important part of our body. It plays such a huge role in our bodies function that when it is working improperly small movements can be difficult and painful. But how do you know if your core is functioning properly? The core is fairly complex and for those who haven’t spent endless hours studying the musculoskeletal system and knowing where over 600 muscles attach and how they contract (thanks PT school) it can be difficult to imagine how the core works.

The “pop can” core analogy

Luckily, there is a common analogy that can make the core a little more easier to understand. The “Pop Can” analogy is a great way to picture and imagine how all the muscles of your core need to work together properly.

And by all means, if you are offended by the the word “pop” you can call it the “Soda Can” analogy. Calm down Californians. And personally, I’m more of a seltzer water kinda gal, hence my “pop can” images. But I digress.

Incontinence, back pain, and even breathing problems can be due to a poor functioning core. So lets dive into the pop can analogy and learn how all the parts need to work together.

The components of the “pop can” core

So we all can picture a pop can right? A perfectly pressurized cylinder with an aligned top and bottom that run perpendicular to each other. A pop can is incredibly stable due to it’s perfect cylindrical shape. And our core is also very strong and stable when it’s in good alignment and functioning properly. So what makes up our “pop can” core.

The Top: The top of the pop can is our diaphragm. This is a muscle that contracts and relaxes rhythmically as we breath.

The Bottom: The bottom is our pelvic floor. The pelvic floor is a “sling” or “hammock” of muscles that holds our bladder and rectum.

The Sides: The sides of the “pop can” are composed of the abdominal muscles and the back muscles. The transverse abdominis muscle is one of the important core muscles that make up the sides of “can”. You can read more about the importance of this muscle and exercises to appropriately activate it in some of my older posts.

What happens when the pop can doesn’t work?

Muscle Pain: So, just like a pop can the top, bottom, and sides of the core all need to be strong and intact to maintain pressure and a nice cylindrical form. But when one part of the “can” is not being activated properly (such as the abdominals) another portion will take on too much of the work. This can lead to problems. Repeatedly using the wrong muscles, such as our low back muscles, can lead to pain and stiffness.

Alignment Issues: Another common problem that can cause difficulty with core muscle function is poor alignment. The top and and the bottom of the “can” need to be parallel and in neutral alignment for proper muscle activation and stability. Things like improper posture, and poor pelvic alignment can make it difficult to activate the spinal stabilizers and maintain proper core pressure.

Low Pressure: Speaking of pressure, this is the third way core stability, incontinence, and back pain can be related to the “pop can” core. A closed pop can with good internal pressure is very hard to crush. So our trunk (or “pop can” core) needs to be strong and appropriately pressurized to keep strength and stability in our body. For example if the bottom (the pelvic floor) is weak it will make maintaining core stability difficult.

Excessive Pressure: Similarly, when excessive pressure is placed on the “pop can” (such as during pregnancy) this can also cause problems. Just like when a pop can bursts in the freezer an over pressurized core can cause one area to become weakened causing issues such as incontinence, back pain, or difficulty breathing.

What’s next?

Hopefully, this pop can analogy can be helpful in understanding how core function relates to things like back pain and incontinence. A strong and stable core is crucial for all movement. So when addressing body problems we like to start from the core and work our way outwards. If you are looking to start strengthening your core I’d recommend starting with your transverse abdominis muscle. Or check out more effective core strengthening exercises on some of my older posts. And coming up I’ll be talking about the bottom of the pop can…the pelvic floor!  So be sure to subscribe to the blog and check back in the coming weeks.

–Monica