Elderly people could one day be relying on a bodysuit, rather than a Zimmer frame, for support.

Scientists in Japan are developing the 'Michelin gran' lycra suit ,which is covered in pairs of inflatable "muscles" which assist the wearer's real muscles.

When they inflate, they help the wearer move their limbs with more strength and stability.

The suit is the creation of Hiroshi Kobayashi, a roboticist from the Science University of Tokyo.

It's a very interesting idea

Sammy Margo, Chartered Society of Physiotherapy

He says that, crucially, the person's own bones and joints act as supports for the inflatable muscles.

The research is featured in New Scientist magazine.

Pressure sensors

The suit mimics the body's system of connecting muscles to bones via tendons.

It could be used to boost the strength of specific muscles, such as biceps or triceps.

The artificial muscles are made up of inflatable rubber tubes surrounded by flexible metal mesh connected at each end to the joints on the suit

When the tube inflates, the mesh bulges, which in turn pulls each end in and shortens the artificial muscle.

Pressure sensors all over the suit would tell the artificial muscles when to kick in.

Scientists have previously worked on steel external skeleton, which can help carers and nurses lift patients.

But exoskeletons need external power sources. The body suit has its own power supply, which researchers say will mean wearers have more independence.

The power comes from compressed air, stored in a series of small canisters within the suit, or in a tank carried on the wearer's back.

'No superpowers'

Development of the suit is still in the early stages.

Only the top half of the suit has been built so far. It is hoped the legs will be ready soon.

The researchers also have to develop a reliable computerised network of pressure sensors to let the wearer control the muscles at will.

They are also experimenting with voice activation for some muscle groups.

But Dr Kobayashi warned that the suit would not give people superhuman powers, and would only be strong enough to carry its own weight, that of the air cylinders and the person's limbs

Sammy Margo, a spokeswoman for the Chartered Society of Physiotherapy, told BBC News Online: "Conceptually, it's a very interesting idea."

But she said there were positive and negative aspects to the suit.

"The downside is that often people are weak because their bodies are telling them 'you're not strong enough to do this.

"But the upside is you could facilitate people to be doing things they couldn't otherwise do."

She said a potential use could be in therapy, where people could 'relearn' how to use their muscles properly.