Do the left half and right halves of the diaphragm of a normal person move exactly the same distance between inhaling and exhaling?
A short answer is that the displacement of the right and left part of the diaphragm during breathing may not be the same.
In humans, the diaphragm is slightly asymmetric—its right half is higher up (superior) to the left half, since the large liver rests beneath the right half of the diaphragm. There is also a theory that the diaphragm is lower on the other side due to the presence of the heart.
The diaphragm muscle is essential for breathing in mammals. Its asymmetric elevation during contraction correlates with morphological features suggestive of inherent left–right (L/R) asymmetry.
Excursion (displacement during breathing) of the right and left part of the diaphragm may or may not be the same, which may differ from case to case.
In most cases, the diaphragm shows a symmetrical respiratory excursion of ~2–10 cm...
The excursion may be somewhat asymmetric and there may be a slight delay or lag on one side, typically the right.