Some joints, such as those in the cranium where rigidity is desirable, dont move at all. Others, such as those in the pelvic area, move very little. But most joints move a lot. Hinge joints, as in our elbows and knees, swing back and forth like doors. Ball-and-socket joints, as in our hip and shoulder, enable bones to twist and turn in many directions while remaining firmly connected to each other.
The movable joints in our bodies thrive on use and deteriorate with disease, injury, neglect or excessive overuse. So the adage "use it or lose it" is particularly apt but in moderation. Even without arthritis, joints tend to stiffen as we age, so regular exercise and stretching become increasingly important.
Click here to go to the joint atlas for an introduction to all the joints in your body.
