Just call her Woah!-prah Winfrey. Oprah took a tumble Saturday during the L.A. stop of her 2020 Vision tour--and ironically, the onstage stumble occurred while she was discussing balance. “Balance doesn’t mean all things are equal or at peace at all times,” the 66-year-old Winfrey said before appearing to trip over her own feet. While the crowd gasped with fear, Oprah responded by declaring, “Wrong shoes!” She also opted to go barefoot for a spell before switching to a comfier kind of footwear. Meanwhile, after video of her gaffe went viral, nemesis 50 Cent joked on Instagram, "Michael Jackson’s ghost tripped her.” As for Oprah, she took to Twitter to thank Jennifer Lopez for joining her onstage before quipping, "Now I’m headed home to ice my knee."