NEW YORK ( TheStreet) -- You may think you know how far you ran or how any calories you burned doing it, but David Putrino knows full well how easy it is to fool oneself when it comes to "quantifying oneself." "The core of my work is using 20-camera motion-capture systems to precisely quantify the body moving in space," said Putrino, co-founder of GesTherapy, an intriguing New York City medical rehab company that turns off-the-shelf video game and PC controllers into a powerful therapy tools for stroke patients. "Then I replicate much of what those high-end systems capture with consumer devices like the Microsoft ( MSFT) Kinect and the Leap Motion Controller." And this NYU, MIT and Harvard researcher has learned a powerful lesson when learning to quantify the self with tools made for fun and games: They work -- with a lot of hard work. "When these tools for play are put to the serious use of measuring body mechanics, weight loss or activity," Putrino said, "that's where we have to be careful about how valid the data is." "You cannot be lazy about the information these devices produce, or bad things start to happen." The engaging, sleep-averse Australian -- who also finds time to contribute to the Brainwriter project that seeks to aid those living with severe aymotrophic lateral sclerosis, or Lou Gerhig's Disease -- knows firsthand what can go right, and wrong, with rehab. "I had a seizure event as a child," he told me. "And the doctors told my mother that I would struggle to recover the full use of my left side." His family simply ignored the prognosis and began years of rigorous rehab, making a commitment to recovery that not only reclaimed the full use of Putrino's body, but turned him into the fit, practicing physical therapist he is today. "I know exactly what rehabilitation can do, if you honestly commit to it," he said. "The body is a magical thing once you face the details of what it can -- and can't -- do."