For the first time in humans, a combination of electrical stimulation and physical therapy has allowed a person previously paralyzed below the waist to regain the ability to move and stand. Rob Summers, 25, was paralyzed below the chest in 2006 after being struck by a car. For 26 months, therapists at the University of Louisville moved Summers' legs in a walking motion as he was suspended above a treadmill by a harness. Then, doctors implanted 16 electrodes on key parts of his spinal cord. Now he is able to stand up using his own leg muscles while holding on to bars for support, bear his own weight for up to four minutes, and take steps on a treadmill with assistance. He's also able to voluntarily move his hips, ankles, and toes, and he's gotten back some bladder and sexual function. "I didn't move a toe for four years," said Summers. "I stood up on the third day they turned the stimulator on," he said. "There are not enough words to describe how I felt."