Your body (specifically your brain) only cares about one thing....surviving. (Mine cares about surviving and pizza)
The most fundamental reflexive activity we do that is absolutely vital to our survival is breath.
No one taught you how to breath. It just happens. (Barring very unfortunate circumstances)
If you put your body in a position where it is difficult to breath, chances are you won't spend a lot of time there and you will shift into a position where it is easier to get air in. Your brain just perceived that position (at that particular moment) as a threat to survival.
Your brain will never sacrifice breathing for movement, even if that given movement is causing pain. At the end of the day, pain is better than death.
But, did you know that your breathing pattern has a major affect on how you are able to move?
Brief Lesson on Breathing
During normal quiet breathing, our ribcage needs to expand in three dimensions (anterior, lateral, posterior). With each exhale it compresses/narrows in the opposite direction.
Picture your lungs like a ballon. When we inhale, the ballon will expand, so the ribcage that encases the lungs, needs to be able to expand (widen) to allow for full expansion of our lungs.
Without getting into too much detail beyond the scope of this post, each inhale is accompanied by an expected motion at every joint. Same goes with each exhale (but opposite).
If we are incapable of efficiently expanding our ribcage in all dimensions, our body will bias whatever position it deems easiest for it to get air in. Remember, breathing is survival.
That positional bias will then have an effect on position of all joints of our body. To what degree depends on any number of variables from body types to activity level to stress levels, etc etc.
Long story short, your breathing pattern affects available range of motion at every joint (upper, lower body AND trunk) and will affect what strategies you use to drive movement.
With every physical therapy assessment, there is some assessment of range of motion at every joint. A cookie cutter approach would assume any limitations in range of motion immediately means that a tight muscle is restricting motion and needs to be stretched.
We now know that to be untrue.
With a deep understanding of breathing mechanics, ribcage positioning and expected joint motions with different phases of respiration, we can identify the true source of your limited range of motion and movement dysfunction.
Our brains make incredible reflexive changes (compensations) to minimize energy expenditure and preserve life.
Unfortunately, our brains do not have the foresight to see how those compensations may lead to pain or limitations down the road.
At the end of the day, survival should always be our first priority. But once our lives are no longer at (perceived) threat, we should have the capacity to normalize breathing mechanics and express all available movement options.