This isn’t the first or even the second time Powelton Village’s Joan White has won this award. A guru among local instructors, she’s strict, with dry humor and a deep anatomical knowledge that informs her form-driven teaching. But why again? Last August, the now 63-year-old White suffered a horseback-riding accident that made Madonna’s look like a boo-boo. Eight broken ribs, a broken vertebra and a partially collapsed lung could have retired her. But she kept teaching. And we’re grateful.