Fixed joints do not move and are connected by fibrous connective tissue, like the skull bones. Slightly moveable joints allow a small amount of movement and are connected firmly by cartilage, such as the vertebrae. Most body joints are synovial joints, which are freely moveable and surrounded by an articular capsule containing synovial fluid to lubricate the joints, making them prone to injuries like dislocations.
2. Fixed Joints – These joints are also called immoveable joints, because they do not move. These joints have no joint cavity and are connected by fibrous connective tissue. The skull bones are connected by fibrous joints.
3. Slightly Moveable Joints – These joints also have no joint cavity and the bones are connected firmly to each other with cartilage. These joints only allow a small amount of movement. The vertebrae are examples of cartilaginous joints.
4. Synovial Joints – Most of the joints in the body are synovial joints. These joints are freely moveable and are characterised by being surrounded by an articular capsule which contains the synovial fluid. Synovial fluid lubricates the joints which supplies nutrients to the cartilage and it contains cells that remove microbes and debris within the joint cavity. Because of the larger range of movements of these joints, there is an increased risk of injury, for example, dislocations. Synovial joints are located mainly in limbs. Many synovial joints also have ligaments either inside or outside the capsule.
