Have you ever wondered “Why is it so important to keep yourself moving to maintain joint health?” Usually with mechanical devices, the more they move then the faster they wear out. Just look at your car tires for example. What makes the human body so different in this respect?
Put simply, because they don’t have a blood supply of their own, joint load and movement is needed to get nutrients into the joint surfaces.
To understand why you first need to know a little but about the joint surface which is known as Articular Cartilage. This Cartilage is present on the ends of bones and is responsible for providing resistance to compression, distributing load, and together with the joint fluid, allowing the near frictionless movement of the surfaces of the joint. Cartilage is made up of cells called chondrocytes, which are contained in a framework consisting of collagen fibers. Embedded within this framework is a special substance called Aggregating Proteoglycans – large molecules that are capable of attracting and holding onto water. When the Proteoglycans bond with water they create the pressure that the cartilage uses to resist load. When the cartilage is compressed during activity the water is pushed out into the collagen fibers and onto the joint surface. When the compressive forces are removed, the water returns to the articular cartilage.
As articular cartilage does not have a direct blood supply, the movement of fluid in and out of the cartilage is the only way of getting nutrition into the cells of the joint surface. This movement of fluid also helps in the removal of waste products from the joint. So in summary, movement is essential for the health of cartilage. In a way it acts like your heart pumping blood to the rest of the body.