The problem is that in some five decades of tests and experiments, none of them alone has performed nearly as well as the body’s actual lubrication system. The three main molecules that have been suggested for the role of lubricant are phospholipids, hyaluronan (a chain-like, polymer molecule) and lubricin (a protein). Moreover, of the many different molecular substances in the joints, several have been proposed to be the main lubrication molecule. Part of the reason that the joint lubrication system had not been revealed until now, says Klein, is that it forms a very thin layer on the cartilage surface, and its properties are not understood. One in three people suffers from osteoarthritis – the most common form of arthritis – by age 65, and nearly one in two does so by age 85 while younger people often develop the disease after sporting or other accidents and there is no cure. Jacob Klein of the Weizmann Institute’s Materials and Interfaces Department, which appeared in Nature Communications, are helping to solve the puzzle of joint lubrication, and they may, in the future, point the way to treatments for problems with this lubrication, especially osteoarthritis. And they do so over and over, every day, for many decades.

As we run or walk, the surfaces of the cartilage in our hip and knee joints slide over one another at high pressures. No man-made lubricant can even come near to meeting the daily demands we make of our joints.

Presage secret compartments