Why Bone Animations Can Distort
So I have had some problems with my bone animations distorting in ways that I didn't want them to.
After researching into this issue, these are the possible reasons I have found:
Unnecessary bones and pivot points - if there are too many bones placed in an area where they aren't needed, this can cause the animation to distort and make the animation look unnatural.
Weighting - it can help to add weighting to parts of the animation. This can change how much certain parts move or how much it moves on a particular axis.