This page is about the joints in the skeleton that allow movement.
If two bones just moved against each other, they would eventually wear away. This can happen in people who have a disease called arthritis. To stop this happening, the ends of the bones in a joint are covered with a tough, smooth substance called cartilage. This is kept slippery by. Tough ligaments join the two bones in the joint and stop it .
The diagram shows theof a joint.
Different types of joint allow different types of movement.
- Ball and socket joints allow movement in more directions. Hip and shoulder joints are ball and socket joints.
The bones cannot move on their own - they need muscles for this to happen.