The point where two bones meet is called a joint. It is responsible for different kinds of movements.
Joints are of three types:
- Immovable or fixed joint: Joints in skull except the lower jaw bone, are immovable.
- Movable joint: This type of joint provides a free movement of the body part.
- Hinge joint: Such joints are present in the knee and elbow. These allow movement in backward and forward direction.
- Ball-and-socket joint: A ball and socket joint is one in which the round end of a bone is into the cavity of another bone.
The hip and shoulder joint are examples of ball and socket joint. This type of joint allow a rotational movement.
- Pivot joint: Pivot joints allow rotation around an axis. The neck and forearm have pivot joint. It allow our neck forward and backward and from side to side.
- Gliding joint: In a gliding joint, bones glide over one another. Present in the ankle and wrist, this joint allows movement from side and back and forth.
- Partially movable joints: They are located in the vertebrae and pelvis. They allow bending and partial movement.