In many flow classes, it’s common to hear the instruction to ‘roll up to standing’ from a standing forward fold. This isn’t something that’s found in traditional yoga practices. In ashtanga yoga, you always rise from a forward fold with a flat back. I also haven’t encountered it in my (admittedly limited) experience with Iyengar yoga. It seems to be an instruction that has made its way into yoga classes via dance. Although it might seem like a harmless alternative, it is something I never teach anymore, and I teach my students in teacher trainings not to teach it either.