Human joints come in many shapes and sizes. They allow us to move and carry out normal activities of daily living. Without joints, we would be rigid and immobile. But joints are often injured, causing pain and discomfort.
The knees, shoulders, ankles, and spine are the most commonly injured joints. Approximately 30 million doctor visits a year are due to knee and shoulder injuries alone. Some 150 million to 200 million cases of back pain send people to a doctor every year--and many of those are related to joint injuries.
How do joints work?
Joints are designed to withstand the loads placed on them and provide a full range of motion. Each joint is made up of at least two surfaces that touch each other and allow for movement. These include ball-and-socket joints such as the hip; hinge joints such as the knee and elbow; and gliding joints, such as those in the spine.
The bones that make up the joint allow movement, but it is the muscles that pull the bones that produce the movement. Muscles are attached to bones by tendons. Bones are connected to bones by ligaments.
Muscles, tendons, and ligaments are attached around each joint at very specific positions, with joint surfaces shaped in exact dimensions. Fluid within most of the joints lubricates the joint surfaces to reduce friction and allow for lifelong use.
How do I keep joints in good shape?
The movements that you perform on a daily basis are critical to long-term joint health, as are proper nutrition, a healthy exercise regimen, and...