On a Friday morning this past February champion sprinter Mike Rodgers got strapped into a safety harness suspended from the ceiling above a custom-built treadmill. “No one's ever fallen, but you can be the first,” he was told. Rodgers smirked and steeled himself to run. He was training for the Olympic trials. But that day he was not completing one of his standard, punishing drills on the track or in the weight room at his gym. Instead he had showed up at a small, white building in Dallas with “Locomotor Performance Laboratory” embossed on the door.