Joints are the places where bones meet. Different kinds of joints allow you to move in different ways.
Your knee can bend in the middle but it can’t swing from side to side. This joint has a hinge like the one that allows you to open and close a door.
The bones that make up your skull start to join up soon after you are born. Once they have fused, none of them allow movement except the hinged jaw joint.
Ball and socket
Your hips are ball and socket joints. They allow you to move your legs in all directions and even to turn them.
Neck bones feature a pivot joint that allows your head to turn.
Wrists have a joint that allows them to turn but not to go right round.
Ankles contain different joints for up and down and side to side movement.
Thank your thumbs
Your thumb is the most flexible of your fingers. You rely on your thumbs whenever you handle delicate objects.
Joints, particularly knee and hip joints, sometimes wear out in old age. When this happens, doctors can remove the worn-out joint and replace it with an artificial one.
Bands of tissue called ligaments act like elastic. They hold your bones together yet still allow you to move.
People whose joints are particularly flexible are called “doublejointed”. The condition can run in families, but people who are doublejointed must practise if they want to keep their ligaments stretchy.