(1) Immovable joints or synarthrosis. These allow no appreciable
movement and the bones are fastened together by cartilage or fibrous tissue.
The bones of the skull are united by one type of immovable joint called a suture.
(2) Slightly movable joints or amphiarthroses. These permit limited
movement and the bony surfaces are connected by fibrocartilage, often in the form of a
disk. These joints are exemplified in the intervertebral spaces and in the symphysis
(3) Freely movable joints or diarthroses. The freely movable joints permit
varying types of movement as discussed below. The articular surfaces of these bones
are covered with hyaline (articular) cartilage and encased by an articular capsule
ligament that is attached to both bones near the articulating end, holding them together.
The cavity of the capsule contains synovial fluid that lubricates the joint. In some joints,
an articular disk is also found between the articulating layers. Most joints of the body
are freely movable (diarthrodial) and may be classified as shown below:
Angular, Rotation, Circumduction
Angular (Single Axis)
b. Types of Joint Movement. Muscles are attached to bones by tendons
(cords of white fibrous connective tissue). Contracting muscles provide the forces
which, when transmitted to the bone, institute various movements. The different types
of movement are described below.
Gliding movement. Limited to a sliding of articular surfaces over each
Adduction. Movement toward the median plane of the body.
Abduction. Movement away from the median plane of the body.
Flexion. Movement to decrease the angle between adjoining parts.
Extension. Movement to increase the angle between adjoining