Gregg Mozgala was born with cerebral palsy, he often wore leg braces until he was 12 but, as Serena Altschul reports, dancing has proved to be a most unlikely medicine for this young man.

It’s early on a Saturday morning, and Sarah Markowitz limbers up before her dance class begins.

Gregg Mozgala, a 31-year-old actor with cerebral palsy, had 12 years of physical therapy while he was growing up. But in the last eight months, a determined choreographer with an unconventional résumé has done what all those therapists could not: She has dramatically changed the way Mr. Mozgala walks.