Arthritis is the number one cause of joint problems. Approximately 43 million people in the U.S. are affected with this disease. One million new patients develop arthritis each year. One in six people are affected by arthritis, or one in three families.
How Joints Work
A joint works like a hinge on a door. It glides open without sound or effort. This is similar to how a healthy knee or hip works. A rusty hinge is similar to an arthritic joint. It is deteriorated to the point that it doesn’t work very well.
In a healthy knee the cartilage cushions the joint or helps it absorb shock during motion. This type of joint is considered a “gliding hinge joint”, although it is more complex than a simple hinge. In an arthritic joint, the surfaces between the bones are worn and uneven. This creates friction, which causes pain.
Other joints in the body include the hip, shoulder and wrist, which work similar to a ball and socket. When arthritis sets in, the joint becomes hard to rotate.