Rob Summers was told he would never walk again after he was hit by a speeding car but was determined to prove doctors wrong

Rob Summers suspended on a treadmill, helping his legs relearn how to walk

Baseball champion Rob Summers was hit by a speeding car in Portland, Oregon, three years ago, which smashed into his legs and left him with appalling injuries. He was told he would spend the rest of his life in a wheelchair at best. But the 25-year-old is now making history – as the first person paralysed from the chest down to stand and take a step unaided.

The small and shaky movements that Summers has achieved spell real hope for all those who have suffered a spinal cord injury, and possibly even for those paralysed by other causes such as stroke.

When he was in hospital, doctors told Summers he would never walk again, he said. "They said that I had no hope and to just give up. My comment was you don't know me very well. I'm going to fight until I get well again." To stand again and take steps, he said, "felt incredible. It was amazing. It made me optimistic and hopeful again for the future. I'm excited at being a part of this."

Summers' legs are able to move because of electrical stimulation from a device implanted in his lower spine. Two hard years of training, suspended over a treadmill with physiotherapists manipulating his legs to stand and walk have helped build up the spinal cord neural network which processes signals to and from his legs.

The real discovery has been that it is not the brain that is in charge of movement, but the legs and the spinal cord.

His achievement is the culmination of many years of hard work and intense scientific endeavour funded by the Christopher and Dana Reeve Foundation, set up to try to find a way to restore movement to the former Superman star Christopher Reeve – who was paralysed in 1995 as the result of a riding accident – and others like him.

Summers, a college baseball player for Oregon State who had helped his team win the college world series just six weeks before the hit and run driver wrecked his life, was exceptionally fit when he was injured.

Although unable to move any part of his legs or feet, he has some residual feeling. This may mean that the astonishing progress made in his case may not be replicable in everybody. But there is now more than hope.

"This is a breakthrough. It opens up a huge opportunity to improve the daily functioning of these individuals ... but we have a long road ahead," said Professor Susan Harkema from the Kentucky spinal cord research centre at the University of Louisville, one of two leading neurologists involved in Summers' treatment.

Harkema describes the impulse from the brain to start walking as "facilitatory". What really starts the walking process, she says, is probably the shifting of weight to one foot.

"The brain is not controlling movement to the extent we thought it was. If you think about walking, it sets up the nervous system to expect information related to walking," she said. That sensory information comes from the legs.

This has been known and accepted in animals for some time, she added, but it was thought it might not be so in humans because of the highly developed brain.

"The spinal cord is smart," said Harkema's chief collaborator, neurologist Professor V Reggie Edgerton from the David Geffen school of medicine at UCLA.

"The neural networks in the lumbosacral spinal cord are capable of initiating full-weight bearing and relatively coordinated stepping without any input from the brain. This is possible, in part, due to information that is sent back from the legs directly to the spinal cord."

The details of the neurologists' work with Summers are published in the Lancet medical journal.

The results need to be replicated in other patients and the neurologists also hope to work with paralysed patients with other kinds of injury. But, said Susan Howley, executive vice president for research at the Reeve Foundation, it demonstrates proof of concept. "It's an exciting development. Where it leads from here is fundamentally a matter of time and money," she said.

Other neuroscientists applauded the work in a commentary in the Lancet. Dr Grégoire Courtine and Dr Rubia van den Brand from Zurich University and Dr Pavel Musienko from St Petersburg wrote that they expected "this novel phenomenon of electrically enabled motor control" would inspire new thinking. They added: "We are entering a new era when the time has come for spinal-cord injured people to move."

Meanwhile, Summers hopes to run and play baseball again one day. It has been, he acknowledged, "one great emotional rollercoaster with highs and lows. There were points of anger and frustration, but I would refocus on my goals." His family, he said, had been incredibly supportive.

He hopes now to make a movie. "My goal is that through making a movie of my life story, I will help the millions of people around the world, paralysed and in wheelchairs, who have lost hope, and show them there is a brighter future ahead."