Joints

JOINTS

•    Joints are places where two or more bones meet.

•    There are three main types of joints present in our body.

Fixed/Immovable joints:

•    Fixed joints do not allow any movement.

•    The joints between the bones of our skull are examples of fixed joints.

Freely movable joints:

•    Freely movable joints can move quite freely and allow a variety of movements.

     Examples: elbow and knee joints.

Slightly movable joints:

•    Slightly movable joints allow very little movement.

     Ex:    joints between most vertebrae.

•    The four major movable joints present in our body are:    

Ball and socket joint:

•    In this type of joint, the ball like surface of one bone fits into a cup-like hollow in the other.

     Ex:    Joints at the hips and the shoulder.

Hip joint                     Shoulder joint

Pivot joint:

•    In this type of joint, the rounded surface of one bone fits into a ring formed by the other, such that one bone is able to rotate over the other.

     Eg: Joint where the neck joins the head.

Neck joint

Hinge joint:

•    This kind of joint provides back and forth movement similar to the hinges of a door.

     E.g.:  Joints at the knee and the elbow.

Knee joint                           Elbow joint

Gliding joint:

•    This kind of joint allows bones to glide over each other, providing little movement in all directions.

     E.g.:  Joints at the ankle and the wrist.

Ankle joint           Wrist joint