Ariana Grande might need a good chiropractor after filming Wicked. Speaking to PEOPLE alongside costar Jonathan Bailey, the singer-actress, 31, confirms that the many haughty hair flips she performed as Oz’s Glinda the Good Witch left her “forever changed.” “I was, I still am, stiff,” she reports after Bailey, 36, asks if she got “physio involved” to toss her blonde wigs behind her just so. “I'm forever changed in a lot of ways emotionally,” Grande says of playing Glinda, before riffing: “But mostly my spinal column. It's not good.