Light activity, such as routine housework, that doesn't take a lot of effort may help stave off disability, according to a recent study HealthDay reported.

Researchers at Northwestern University in Illinois found that pushing a shopping cart or a vacuum could help people with or at risk of knee arthritis avoid developing disabilities as they age. They found that people who spent more than four hours a day doing light physical activity had more than a 30 percent reduction in their risk for developing a disability.

"Our findings provide encouragement for adults who may not be candidates to increase physical activity intensity due to health limitations," Dorothy Dunlop, lead author of the study and professor of medicine at Northwestern University Feinberg School of Medicine, said in a statement. "Even among those who did almost no moderate activity, the more light activity they did, the less likely they were to develop disability."

For the study, researchers examined a group of almost 1,700 adults, between the ages of 45 and 79, from the Osteoarthritis Initiative study who were free of disability but were at elevated risk for developing it because they had knee osteoarthritic o other risk factors for knee osteoarthritis, such as obesity.

They had study participants wear an accelerometer around the hip during their waking hours for about a week. The device measured the intensity of their daily movements, giving the study team an idea how much time they spent in vigorous, moderate or light physical activities.

Two years after collecting the results from the accelerometer, participants were surveyed and asked about the development of disabilities.

They found that more time spent in moderate or vigorous activity was associated with lower reports of disabilities. They also found that greater time spent in light intensity activities also was related to fewer disabilities, even after accounting for time spent in moderate activities.

"We were delighted to see that more time spent during the day, simply moving your body, even at a light intensity, may reduce disability," Dunlop said. "Now people with health problems or physical limitations, who cannot increase the intensity of their activity, have a starting place in the effort to stay independent."

The findings were recently published in the British Medical Journal.