Scientists working to help astronauts regain their balance after extended flights in zero gravity have found a way to use the research to help elderly people avoid catastrophic falls.

Erez Lieberman and Katharine Forth are working on an insole that contains sensors that read how well a person is balancing. They say a damaging fall is preceded by numerous warnings, similar to how high cholesterol and elevated blood pressure points to a coming heart attack.

The iShoe insole would gather information for doctors before elderly people fall, they say.

The National Osteoporosis Foundation in the U.S. estimates 300,000 people annually suffer hip fractures, which are often caused by falls. An average of 24 per cent of hip fracture patients age 50 and over die within a year of the fracture.

Many fall victims who don't die within a year end up being disabled the rest of their lives.

"It's a huge issue," said Elinor Ginzler of the AARP. "It significantly impairs your ability to stay independent, which is what people want."

The idea for the iShoe came to Lieberman while the graduate student was working at NASA last summer on a project to help astronauts regain balance after months in zero gravity. The work is part of preparations for long space missions, such as trips to Mars, that require astronauts to perform complicated tasks on the terrain soon after landing.

The balance research seemed to Lieberman to have obvious applications for the elderly.

He and Forth, a visiting scientist at NASA who also works on the iShoe, had been touched personally by the issue of elderly falls, with each seeing a grandmother's health rapidly deteriorate after such an accident.

"It was something that has kind of been on my mind in general, and once I started looking at balance it became very clear it would have applications in that direction," Lieberman said.

Device to cost about $100

NASA tests balance with an expensive device about the size of a phone booth. Lieberman and Forth say the iShoe insole, slipped inside any shoe, solves the problem of portability and affordability, since the device would cost about $100 US.

The iShoe researchers used some of their own work and previous NASA data to determine how pressure is distributed on the foot by people with balance problems, compared to those with good balance.

They then were able to determine certain pressure patterns that show up when people are struggling with balance.

The iShoe, with a half dozen sensors, is not an instant alarm, though it will send out a signal if the wearer actually falls. It's more like a data recorder that the user can take to a doctor or balance specialist for help if the dangerous pressure patterns are seen.

Balance problems are caused by many factors, including deteriorating muscle tone, bad vision and inner ear problems, and the possible solutions can be as simple as a tai chi exercise to build strength.

"Poor balance isn't something you have to accept. ... You can help yourself, you can improve balance," Forth said.

The iShoe has a way to go to reach the market. It's still being tested to ensure it can hold up under constant foot pounding, and Lieberman and Forth are still perfecting the software that identifies the faulty pressure patterns. Research involving elderly people is just getting under way.

Lieberman estimates $1 million US is needed for a broad clinical trial, and $3 million to $4 million to bring the insole to market.

The company has applied for a patent as well as U.S. government funding. Once funding is obtained, the iShoe could be for sale in 18 months, Lieberman said.