By Jane Elliott
Health reporter, BBC News
Andy concentrates on his gait
As Andy Long walks through the unfamiliar city streets his eyes are on the grey buildings ahead of him and the sky above.
He knows the road ahead is smooth so has no need to look at his feet.
Andy sets his own pace and, for a brief time, he is able to forget that he usually needs a stick to aid his walking following a stroke six years ago.
Using clever computer wizardry, researcher Wendy Powell at Portsmouth University has been able to create a special treadmill that enables people like Andy to walk better and faster.
Tricking the brain
Hopes are high that the computer can now be adapted to aid other aspects of rehabilitation.
Wendy said her system "tricks" the brain into walking longer and faster than they usually would and so aiding their recovery.
"We have got a specially adapted treadmill that is linked in to a virtual reality system so a little bit like a computer game.
"The particularly interesting aspect, in terms of the research we are doing here, is that we have found that it we manipulate the virtual reality so that people think they are moving slower than they are what happens is that they move faster and better.
"They do not realise they are putting any more effort in and they are not feeling any more pain, in fact they are less anxious than normal.
"They have a better quality of walking so it has huge implications for recovery," said Wendy, a former chiropractor.
The system, which is currently undergoing clinical trials in both Portsmouth and Canada, is already providing promising early results suggesting that those using the system experience less pain than traditional physiotherapy.
"The virtual system encourages patients to walk more quickly and for longer, almost without them realising it.
"We're effectively fooling the brain and the body," said Wendy.
Wendy says the computer aids walking
The system can be used to help people who have had strokes, osteoarthritis and falls.
As well as the city-scape, patients can take walks in the forest and mountains and are encouraged to pick up and collect objects, which encourages them to do exercise they otherwise might find dull.
Wendy said many patients were surprised to hear their responses had improved by up to 20% on the machine.
Andy, who describes the system as "magic" said it is ideal for stroke survivors like himself, who find it difficult to use a normal treadmill.
Andy, who had his stroke in 2002 was left with a loss of speech and weakness down his right side - doctors feared he would never walk or talk again.
He also had a heart attack the following year.
Now he can walk short distances with a stick and his speech is improving.
His partner Di Summers said she had noticed even more improvements since his two sessions on the virtual treadmill and he is now part of the clinical trial.
"When, like Andy, people walk with a stick, they automatically lean to one side.
"This treadmill keeps them upright and enables them to adjust their balance better.
"Because it is a virtual reality, Andy can see things on the screen as he is walking along so he is not conscious how slow or fast he is going, as his mind is occupied.
"On a normal treadmill you have nowhere to look but your feet, and that is where people lose their balance.
"If he can get to use it on a regular basis he will make great strides," she said.
Di said she is just sorry that the technology was not around when Andy first started his rehabilitation.
"If this was available maybe three or four years ago he might not be walking with a stick now," she added.
Dr Jane Williams, a consultant nurse in stroke care at Queen Mary's Hospital, Portsmouth, said the system has huge potential, and could one day be used to teach people to drive again or re-learn work skills.
She said she hoped adaptations could be added to train patients to walk in high winds or navigate other pedestrians - something her patients had told her was difficult.
"It is just such a fantastic system for helping with rehabilitation," she said.
Andrea Lane from The Stroke Association added: "We look forward to seeing the results of these clinical trials and the impact they may have."