My kid loves heavy metal music, which means he's into headbanging. That's fine with me, I encourage his enthusiasm, but I'm concerned that he could injure himself when he really throws himself into the music. Are there particular moves that are considered safer than others? Speeds or angles that should be avoided? At his age, he'd probably suffer nothing worse than a headache or a crick in the neck, but better safe than sorry, especially since epilepsy and migraine run in the family.