For some reason i've encountered this weird bug a few times now, or at least i think it's a bug.
For some reason after 1 turn of judo, the arms sometimes seem to be "mangled/zigzaggy/melding to eachother" in the preview, and a turn after that, it's for sure either the arms break, or the hands come off, no matter where you move the arms, they will break. It's very annoying =(
EDIT: Most often it happens if you contract abs while doing the standard doublegrab.