What could a sodacan tell us about core stability?

Posted by

We often hear about the connection and interplay between the hips and the lumbar spine (lower back).  This is important because the position of your lumbar spine may indicate how well your “core” is firing.  In this article, I want to take a minute to zoom out of the human body and bring your attention to the position of your rib cage/shoulders/head or “upper trunk” and their relationship to your low back/hips or “lower trunk”.  

 Most people would point to their abdomen or low back when you ask them to indicate where they think their core is.  This is not wrong by any means but an efficient core should extend further up the body.  The position of your upper trunk in its vertical relationship to the lower trunk may be an indicator of how efficient your core may engage automatically.  In fact, through recent developments in the field of movement, we are starting to understand that the “core” extends all the way up to the roof of the mouth called rugae, where your tongue can create negative pressure back to diaphragm and pelvic floor musculatures to create intra-abdominal pressure (IAP).  Mary Massery, PT has proposed the Soda-Pop Can Model of Postural Support, in which she describes the glottis (top of the vocal cord) to the top of a soda-pop can.  If you open the top of a soda-pop can, it can easily be deflated and reshaped.  A can that is closed creates pressure within the can, which is crucial to not only the shape of a soda-pop can but that imagery also relates to the function of your core and maintaining good postural control. 


As mentioned earlier, the vertical alignment of how body parts stack on top of each other is important to how they might function.  This is especially true in what your resting position is in standing or sitting and how your body responds to movement and external load (running/walking or picking up a weighted item). 

 So, how can you quickly check this on yourself? 

 Use a Mirror!  Seeing is believing.   

  • Get a front view of yourself in the mirror.   
  • Do the shoulders sit evenly on your pelvic girdle/hips and down to your feet? 
  • Is your head resting in the middle of your body or is it tilted one particular way?  
  • Get a side view of yourself in the mirror and draw an imaginary line from your ear to your rib cage to your hip and even down to your feet.   
  • Do they line up or is your rib cage sitting behind your pelvic girdle and hips? 
  • Is your rib cage resting and pointed down towards your pelvic girdle and respectively, is your pelvic girdle positioned and pointed towards your rib cage? 
  • What happens when you hold a weighted item in your hands?  Do you remain vertical or is your habit to sway back or forward to meet the demand of the weight? 
  • Do you feel like you can rest and settle in this position? 

 The ability to find good alignment and control the position is a prerequisite for efficient and optimal movement.  Poor alignment in static and dynamic postures can create unwanted stresses and compensations in your body over time.  It is an efficient pressure system within a well-positioned structure that creates optimal function of the human body.  Without looking at your body as a whole, you may not be getting a true picture of your function.  If you are having trouble picturing yourself or getting yourself to where you feel you like you should be, we can help you!  Please contact our office to set up an initial evaluation and one of our functional manual therapist will be able to help meet your functional goal.  

 –Young J. Cho, PT, DPT, CFMT


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s