That's pretty much what I was thinking too, hence my line of inquiry, Esther. There's a lot about rigging I haven't a clue about, but I understand that in order for mesh to deform properly in extreme flexion and extension positions, one has to be mindful of edgeloops and mesh density. Which is one area that apparently the V4 developers had to compromise on: polygon count vs reasonable mesh density in the right areas. Beyond that, it's all a bit of a grey area.

How grey? Charcoal? I'm wide open for correction and illumination...

Monterey/Mint21.x/Win10 - Blender3.x - PP11.3(cm) - Musescore3.6.2

Wir sind gewohnt, daß die Menschen verhöhnen was sie nicht verstehen
[it is clear that humans have contempt for that which they do not understand] 

Metaphor of Chooks