Robert Wickens takes a breath, shifts his weight, and sends a thin leg swinging forward. For a single weightless moment, the paralyzed man appears to be walking.
Then his sneaker lands, catches on the edge, stutters across the treadmill’s slow belt. One of the three cheerful therapists kneeling around him reaches out, correcting the situation with a practiced hand. His foot swings back, he takes another step, and the process repeats.