Realistic models of human joints are helping researchers learn more about how the body's natural joint lubricant prevents wear and tear that can lead to osteoarthritis.

The team, from Duke University's Pratt School of Engineering in Durham, N.C., found that a component of joint fluid called lubricin does more than simply reduce friction -- it forms a thin barrier that repels joint surfaces in order to prevent them from coming into contact with one another.

Lubricin, in combination with another joint fluid component called hyaluronic acid (HA), provides an even greater protective effect for joints than either of the two components on their own, the scientists also found.

"In the healthy joint, the intact superficial surface layer of cartilage provides an extremely efficient bearing surface with an apparently very low coefficient of friction," researcher Stefan Zauscher, assistant professor of mechanical engineering and materials science, said in a prepared statement.

"Any damage to this superficial zone or absence of lubricating factors may be the cause of a cascade of mechanical failures in joints that ultimately leads to the onset of osteoarthritis," he said.

The findings were expected to be presented Wednesday at a meeting of the American Chemical Society in Atlanta.