Chris Tagatac thought he would never walk again. He fell 25 feet from his Vermont roof in July 2011, and was paralyzed from the sternum down.
But six months later, with the aid of a wearable robot called Ekso (short for exoskeleton), he took his first steps -- 52 of them, to be exact.
"The first thing my mother did was put her hand to her mouth and said, 'amazing,'" Tagatac, 49, told ABCNews.com. "When my daughter saw me walk for the first time after six or seven months, she looked at me and said, 'I forgot how tall you were.'"
Tagatac is one of 12 patients using the Ekso for a study under Dr. Gail Forrest, who directs the Kessler Foundation's NeuroRecovery Network, and her preliminary findings showed that patients took in more oxygen when they were standing and walking compared with the resting position, in addition to other health benefits. She also saw increased muscle "firing" or electrical activity in paraplegics' lower legs, but that's because muscles are being stretched, not because they are becoming functional again.
"We're going from these being just perhaps gimmicks that allow people to stand and walk, and we're starting to see that people using these things could actually benefit from them," said Dr. Trevor Dyson-Hudson, the director of spinal cord injury research at the Kessler Foundation. "These are all very early results, but it's a huge potential that these things could perhaps be incorporated into rehabilitation."
Versions of the Ekso have been around since 2010, and 11 other centers are using it. Forrest said her new research involves attaching external electrodes to patients' bodies to record data about how they respond to the device. After collecting data for a few months, Forrest is already seeing evidence that patients benefit physically from the Ekso -- not to mention the emotional boost patients get from being able to look people in the eye.
Forrest presented her findings Monday at a meeting in Las Vegas, and is continuing to research patients' cardiovascular, muscular system and circulatory systems, among other things.
Since Tagatac had the natural body awareness of an athlete before his accident, and his injury was recent enough that standing doesn't cause the dramatic change in his blood pressure common with long-term wheelchair-bound patients, he was invited to participate in an Ekso study three days a week.
"I consider myself extremely lucky to be chosen," he said. "After being told six months before that I'll never be able to walk again, and to be able to take that that first step six months after being injured was amazing."
At his last session, Tagatac walked 3,000 steps in one hour.
"His ability to improve on the device was amazing," said Forrest, explaining that this indicates a "training effect," which has health benefits like exercise. It shows that the machine isn't doing all the work, and the machine engages his lungs and heart -- even his leg muscles.
"Somehow electricity is getting down to my legs," Tagatac said. "I don't really know if it's because I'm upright or because when I take a step, maybe there's some muscle memory in the body that says, 'Oh, I've done this before.' Maybe it's a signal. I don't really know."
This doesn't signify a return of muscle functionality, but the firing could reduce muscular atrophy in some patients, Forrest said. She'll need to do more research to be sure.