Leg boost for stroke patients

A stroke can leave patients disabled

Scientists have devised a way of getting partially-paralysed stroke patients walking - by using their "good" leg to teach the other one.

A stroke in a particular part of the brain may leave one side of the body paralysed, while the other is unaffected.

Doctors have known for a long time that keeping the affected limb moving is beneficial.

Electrodes can be placed in nerves controlling key leg muscles to spark them into action.

However, it can be difficult to mimic the complex movement walking entails.

Normally, a manual switch on the heel of the affected leg detects when the unaffected one has moved forward, and then stimulates the necessary muscles.

Nerve implants

The latest research, detailed in New Scientist magazine, involves a series of sensors placed over different muscles in the healthy leg.

These are linked by a computer to 11 implanted electrodes in the paralysed leg.

This allows this leg to respond far more accurately to what the other leg is doing.

Two stroke patients trialling the technique at Hokkaido University in Sapporo, Japan, have not only been able to walk unaided, but have also managed to stand and sit down.

The scientists behind the device claim that it overcomes the problem of "spasticity" - involuntary muscular spasms - by tuning the leg muscles to move in concert with each other.

However, they say it could be five years before their invention makes it onto the market.

Dr Nick Donaldson, from University College London, said that the idea of electrically stimulating the muscles of stroke patients was not a new one, but many more patients could potentially benefit.

He said: "Some estimates suggest that, across Europe, there are 10,000 new suitable patients a year.

"That's a big market, but what we need is a company prepared to take it on and produce something that can be obtained on the NHS."