twitching
Motions that are sudden, involuntary, sharp movements in response to agitation or stimulation. See flinch for similar motions in response to surprise or shock.
Use for momentary motions, not for sustained motions like shivering or trembling.
Usually denoted by jagged motion lines or the moving body part having a jagged outline. May be animated without these techniques.
For the website, see Twitch.