Character is slightly twiching

I am trying to animate various characters, and have noticed that the arms will slightly twitch and move, even though I am being still. I have played around with the sensitivity, Limb IK...and it still records with the slight movements. It's not smooth. IS this a problem for others? Is it a problem with my computer? Although I have more than the basic requirements to run Character Animator. Could my background be too busy while recording?