The Diaphragm
The diaphragm plays several key roles in the body from breathing to trunk stability.
When we have flexed posture, the diaphragm gets compressed and then shrinks since it is not able to fully expand/contract for proper breathing making us breathe more shallow, restricting intra-abdominal pressure and impacts the whole body by not getting enough oxygen.
This restriction also impacts and shrinks thoracolumbar fascia along the spine where the diaphragm attaches and influences trunk stability since proper breathing plays an important role in maintaining intra-abdomal pressure which is important for balancing and loading tasks of daily living.
There’s a lot to be said about the diaphragm - and as things relate to fascial - it’s all connected.