Imagine taking a walk through Troy in say 1193 BC, dodging Agamemnon and being chased by the Greeks. You might have in mind the latest video game. Figure, however, playing that game not from the comfort of your arm chair but whilst pitting your actual physical strength against that of a virtual Agamemnon. Sounds far-fetched? Not to the ears of scientists in Germany, with the launch, this month of Project Cyberwalk.

Jonathan Marshall: A special platform-cum-treadmill is about to make our interaction with virtual worlds more of a reality. No longer will we breach the walls of the Trojan citadel at the click of a mouse. Instead we will be dodging Agamemnon by literally walking and changing direction on a special platform. The platform may help people with neurological impairments and improve the training of athletes.

Dr. Marc Ernst of the Max Planck Institute for Biological Cybernetics in Tübingen: What you want to do is a treadmill but all these treadmills as you know from gym, they’re going in one direction. So what you need, to go omnidirectional, is, you have to activate the platform in different directions. So our vision at the moment is that you walk on many thousands of small balls which you can activate from below with a regular treadmill and this is sitting on a turntable. This way the turntable plus the linear treadmill gives you the freedom to go omnidirectional.

Jonathan Marshall: Wearing goggles fitted with small projectors, the user stands in the middle of a five metre by five metre adapted treadmill. As the user walks, the balls on the surface of the platform will drag him or her back to the centre. As for chasing a virtual Agamemnon, Dr Ernst is not raising his hopes too high yet. There are technical difficulties that need to be overcome. If the images projected inside the goggles and the treadmill move out of sync with the human, he or she will lose balance. Video cameras, therefore, calculate the body position relative to the platform. If the user chooses to run:

Dr. Marc Ernst: We have to rotate the belt through ninety degrees

Jonathan Marshall: We are literally running a race against computer processing power and humans are winning:

Dr. Marc Ernst: We need the fastest machine that there is and that is not enough.

Jonathan Marshall: Crawling, rolling and doing the splits are, however, all possible in this new virtual playground:

Dr. Marc Ernst: But that is what you want, you want to have both feet basically in the same direction or otherwise you will twist your foot.

Jonathan Marshall: Apart from this high-tech gymnasium, this project will also bring real scientific advances. In our natural environment conditions change quickly, for example, the amount of carbon dioxide in the atmosphere. In virtual worlds conditions can be kept constant, thereby making, for example, the development of training techniques for sportsmen, more effective. In medicine, Project Cyberwalk may well prove revolutionary in helping those with neurological diseases:

Dr. Marc Ernst: So far, at the moment, what we have are linear treadmills, so you can have only forces that go in one direction but this, for the balance disorders, is probably not the right thing to do. What you want to have are lateral forces as well and only practice walking on such a device for a long time, you can do special programmes for helping these people to walk again.

Jonathan Marshall: And people who have suffered from strokes will be able to train specific parts of their body in a controlled safe environment. And who knows in years to come this may be the latest tool to keeping fit and thus helping to prevent that stroke from ever happening in the first place.