Not what you want to see.
I have had this appear in front of me when pregnant women get up as they are wont to do (pretending that they can still do what they could when not ‘with child’).
Mainly seen when getting up and not rolling onto their sides first.
Also – after birthing – and still breastfeeding (ligaments are not as rigid).
I have seen a perfectly connected lower belly completely open up with her teaching advanced yoga. A woman’s body is vulnerable when she is in the state to make more children. Many small children I have found to have gaping holes where they should be connected – and no one seems to have noticed.
As here.
On a small boy – upper muscle separation Lower body muscle separation
This is fixable – with application.
We could ponder “was the body made properly?”
Usually I would say always.
The complete (and hard edges) involvement is often softened through regular use of this technique – as has happened with my niece – plus she is mindful of her movements to encourage the X criss-cross action of these muscles to rebind themselves.