Uhhh...I happen to sort-of disagree...
When I was going through it, I most definitely rocked back and forth on the ground, I believe it to be a sub-conscience action that prevents him from doing anything physical and it helps calm the mind considerably...it makes you feel safe for use in desperation when you fear/know that your gonna do something very bad...
Negative voices are also a symptom....unfortunately since he is aggressive I cant offer any advice, this is due to some other negative personality trait unrelated to schizo...Keep in mind I'm not a doctor but I think that's what is going on...