Question

Name the joint that enables the movement from side to side.

Answer 1

Hint: This joint is responsible for the twisting movement that is observed between the bones of the forearm and also, in the rotational movement of the skull.

Complete Answer:
The pivotal joint allows the rotation of bone about a single axis. It allows both external and internal rotation. The joint of the atlas and the axis below the skull enables the movement of the head from side to side.

Additional information:
A joint is a place where two bones contact each other to bring about various movements in our body. The type of joint present will decide the nature and the extent of movement. We can walk, we can run, we can write, speak, etc., which are all made possible only because of the involvement of various joints present in our body.
Joints are classified depending on their structural and functional aspects.
Structural classification of joints
Structurally joints are classified into three types.
1. Fibrous joints
2. Cartilaginous joints
3. Synovial joints
The following table gives the structural classification, nature of movements along with the examples of these joints.

Structural classification of joints	Nature of these joints	Examples
Fibrous joints	Non-movable joints	The rib cage, upper jaw, the backbone
Cartilaginous joints	Partially movable joints	The Spinal cord
Synovial joints	Highly flexible joint	Neck joint, shoulder joint, knee joint

Functional classification: Depending upon the nature and extent of movement, joints are classified into ball and socket joint, pivotal joint, hinge joint, condyloid joint, gliding joint, and saddle joint.

Note: Pivotal joint plays an important role in the flexibility of the skeletal muscle, hence makes the skeletal movement rigid as well as stiff. The pivot joints are affected due to various diseases such as ankylosing spondylitis (it is an inflammatory disease where the bones present in the spine will fuse together) and ankylosis (the complication of arthritis).