I'm not sure what you mean when you say you're using skeletal animation to "move images", but for a head-turning animation you will need to have multiple images of the character's head drawn from at varying angles. I'm not sure what program you're working with (Spine maybe?) but if you could show us some screenshots, that'd help. You might have to draw each frame from scratch, but if you're using a program like Photoshop you can use onion-skin to make sure all of your frames are still in proportion.
As for what I mean when I say "multiple images of the character's head drawn from at varying angles", here's a reference:
Hello,
Thank you for the reply. It really answers my question.
Yes, one of the challenge for me I believe that if I re-draw the head in different angles, would those drawings will still be in proportion with each other?
This onion-skin feature interests me, but I use Inkscape to draw, is there any similar feature in Inkscape? Anyway, I will try to Google it too..
Thanks.