In the past three years, Brooke Eby has gone from Peloton classes to a walker to a wheelchair. In her late 20s, Eby, now 36, noticed a tightness in her left calf that she didn’t understand. The following year, while walking with her Salesforce colleagues in New York City, she couldn’t keep up. She later started limping, unable to lift the front part of her left foot, a symptom called foot drop, which led her to countless appointments with various specialists and doctors.