Types of Joints

Ball and Socket Joint

 This joint can be explained with the help of the following example:

• Take a paper ; roll it in the form of a cylinder
• Take a ball , make a small hole in it and fix the cylinder into the ball, you can stick the cylinder with the ball. 
• Now put the ball in a small bowl.

• Here, your arm is like a paper cylinder and its end is like a ball.
• Your shoulder is like a bowl to which your arm is joined.
• Rounded end of one bone fits into the hollow space (Cavity) of another bone.

These joints allow movement in all direction. In the ball and socket joint, one end of the bone has a round shape like a ‘ball’ which fits into a ‘socket’ in the other bone.

Example - Thigh bone and hip bone are joined together through a ball and socket joint.

Pivotal Joint:

• In this joint, a cylindrical bone turns in a ring-type bone.
• The joint where our neck joins the head is the pivotal joint.
• The pivot joints allow rotation around an axis.
• Pivotal joint helps to bend our head forward and backward ; it also allows to turn our head to our right or left.
• Pivot joints occur in the neck and forearm.

Hinge Joints:

• Hinge joint allows only back and forth movements just like opening and closing the door.
• Doors have hinge which allow them to move back and forth.
• Parts of the body which have these joints are knee, elbow,knuckles(finger joints) and jaw.

Fixed Joints

• Fixed joints are those where bones cannot move at these joints.
• In fixed joints, the bones are held firmly together by strong fibres.
• The fixed joints are immovable joints.
• The function of fixed joints is to provide strength and support to the body or to protect delicate organs (like brain) which cannot withstand any kind of deformation.

For Example- We can only move the lower jaw of our face because the upper jaw and the rest of the head has fixed joints.

Table for Different types of Joints: