Joint: Its types (Movable, Immovable, Ball and socket) and its features
A joint is the junction of two or more bones, called. Various types of joints are shown in the following table.
Types of Joints Type Features
Movable – Two or more bones are held together by means of ligaments, muscles, and tendons. Movement is possible between bones. Three kinds of movable joints are ball and socket joints, hinge joints, and joints with limited movements.
Immovable – In immovable joints the bones are permanently fixed to each other. Movement is not possible between the bones. Chances of sprain or dislocation are minimal.
Ball and socket – The round head of one bone fits in cup – shaped cavity of another bone. Movement is possible between planes and directions. Examples are shoulder and hip joints.
Hinge – Movements is possible only in one plane, e.g. elbow and knee joints.
Joints with limited movements – Only limited degree of movements is possible between bones forming the joints, e.g. wrist joint, intervertebral joints and joints of ribs and vertebrae.
Ligaments are tough fibrous structures that bind bones to one at joints. The part of a joint is covered by fibrous joint capsule. The ends of bones forming the joint are covered by smooth articular cartilage. The joint cavity is lined by smooth membrane (synovial membrane) and filled with lubricating fluid (synovial fluid).