Pistorius has won four Paralympic gold medals. But his quest to run against able-bodied athletes in the Olympics was long and complicated, involving scientists and lawyers. In the purest sport, it wasn’t just a question of whether he was fast enough, but whether his blades gave him an advantage. The Oscar Pistorius case became — and continues to be — a debate about fair play and the right to compete.

Dr. Robert Gailey is a University of Miami physical therapy professor and scientist who has worked with hundreds of amputee athletes and with Pistorius since he was a 17-year-old rugby-player-turned-sprinter using clunky old prosthetics. Gailey has been instrumental in Pistorius’ development and in his successful appeal of a ban by track’s governing body, the IAAF.

“He really has no advantage,” Gailey said. “He has a disadvantage. The major power generator for an able-bodied 400-meter runner is his ankles. Oscar doesn’t have ankles.”

Pistorius generates power from his hips, because he has lived his whole life that way. He is hindered at the start because he cannot jump from the blocks; he has to pull out. Able-bodied sprinters can keep their bodies low and wind resistant for the first 30meters. Pistorius pops up on his toes. In the turns, able-bodied athletes can drive off their outside foot. But Pistorius’ feet have no side-to-side motion. He has to keep his balance. Nor does he have a longer stride length, as the IAAF argued in a study that Gailey debunked.

Gailey’s research showed that able-bodied athletes get a 250 percent energy return when they’re sprinting compared with 80 percent for Pistorius.

At first, the IAAF welcomed the Pistorius spectacle and feel-good story. But as his times improved, the IAAF got nervous. What if he opened a Pandora’s box and all sorts of athletes with disabilities clamored to compete? What if it became doping by custom-constructed artificial limbs? Science could make sports unrecognizable — in fact it already has if you compare today’s Olympics to those of ancient Greece.

“But that’s the future,” Grenada’s Kirani James said after running his 400. “I see Oscar as another athlete, another competitor and, most importantly, as another person. We should respect and admire him.”

Pistorius’ fellow runners, whose own Olympic races were ignored, put it plainly.

“I’ve seen him throw up during practice like anybody else,” Dominica’s Erison Hurtault said. “There are guys out there who take drugs, so he’s the least of my worries.”

Said Florida’s Tony McQuay: “It’s not like he set a world record the first day he ran. He has a great heart. He’s working hard, just like the rest of us.”

Just like the rest of us. Pistorius is redefining “normal,” whatever that means. It’s an evolving, expanding notion.

Gailey has witnessed the transformation.

“The guys who came home from Vietnam were told, ‘Pick a wheelchair,’ ” said Gailey, an advisor to the U.S. Department of Defense on its amputee rehab program. “Now, when I visit patients who lost their limbs in Iraq or Afghanistan, I ask them, ‘What did you do before and what do you want to do? Triathlons? Mountain-climbing?’ ”

He recalled a 1984 basketball game between amputees.

“A kid came off the court, removed his leg and his stump was a bloody mess,” Gailey said. “I told him he couldn’t go back in. He said, ‘Dude, we’re down four points,’ cleaned himself up and went back out like any other athlete.”

Gailey knows that thousands of people with limb loss have been inspired by Pistorius’ no-limits imagination. He wanted to run. So he put on his legs and ran.