After you've injured your spinal cord, getting a "motor complete" diagnosis means you're unable to move your legs—or anything on your body, below the injury—under your own volition. Stay "motor complete" for two years and the evidence says you'll never move those areas on your own again. But the prognosis is now a bit different for four hardworking, young(ish) men.

In a new study, researchers treated four men with spinal cord injuries with a combination of mild electrical stimulation to the spine and intense physical therapy. The men regained the ability to move their legs, knees, ankles and toes after being paralyzed for two years or more.

The study follows a 2011 announcement that the same regimen worked for one man, Rob Summers. Over time, Summers was able to stand for a few minutes without help. He could also take steps on a treadmill, with help bearing some of his body weight and keeping him balanced.