Joints Without Movement

There are about 200 bone joints in the human body. Some provide movement of various parts of the skeleton, while others, inactive, serve to support and connect its other parts.

A striking example of fixed joints is the connection of the skull bones with serrated sutures. Other connections, inactive, allow small movements. A typical example of this is the pubic symphysis, which connects the two pelvic bones, but is actually immobile.

Movable joints provide most of our movements. The ends of the bones have a variety of shapes and articulate in different ways. For example, in condylar joints such as the knee, one surface has a convex elliptical shape, while the other, articulating with it, has a concave shape. Trochlear joints, such as the elbow, are shaped like a block. The cylindrical joint is similar to a cylinder rotating around its axis; it serves to connect the radius and ulna bones.