Arm and body "rotating"? -help

Hi, im wondering, this video, was created in toon boom studio, but how do they do the sort of “rotating under arm” if you now what i mean at 1:00, and then shortly after, his entire body starts rotating, how is that done?


Select your arm and using the transform tool, hover near one of the corners until your cursor turns into a curved double-arrow icon and click-drag in the direction of the rotation movement. Don’t forget to make the keyframe a motion keyframe (non-constant segment) so that the rotation movement Interpolates to the next keyframe.