Classification of Joints

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Anatomy > Gray's Anatomy of the Human Body > III. Syndesmology > 3. Classification of Joints

Henry Gray (1821–1865). Anatomy of the Human Body. 1918.

Classification of Joints

In human anatomy, the classification of joints (or articulations) is based on the structure of the joint and the type and degree of movement it permits. Joints are generally categorized into three major classes:

• Synarthroses – immovable joints
• Amphiarthroses – slightly movable joints
• Diarthroses – freely movable joints

Synarthroses (Immovable Joints)

Synarthroses are joints where adjacent bones are connected by fibrous tissue or hyaline cartilage, with no appreciable movement. These are typical of joints found in the skull, except for the temporomandibular joint.

There are four primary types of synarthrosis:

Suture

A fibrous joint found exclusively in the skull. Sutures are further classified as:

• Sutura dentata – interlocking, tooth-like projections (e.g., between parietal bones)
• Sutura serrata – saw-like articulating edges (e.g., between the frontal bone halves)
• Sutura limbosa – beveled overlapping margins (e.g., coronal suture)
• Sutura squamosa – overlapping beveled edges (e.g., squamous suture)
• Sutura harmonia – simple apposition without interlocking (e.g., between maxillae)

Section across the sagittal suture

Schindylesis

A joint where a thin plate of bone is inserted into a fissure between two other bones (e.g., rostrum of sphenoid articulating with the vomer).

Gomphosis

A peg-and-socket joint, seen in the teeth articulating with the alveolar process of the maxilla or mandible.

Synchondrosis

A cartilaginous joint where bones are connected by hyaline cartilage. It is typically temporary and ossifies with age. Examples include:

• Spheno-occipital synchondrosis
• Epiphyseal plates in long bones

Occipitosphenoid synchondrosis of an infant

Amphiarthroses (Slightly Movable Joints)

These joints allow limited movement and are connected by fibrocartilage or interosseous ligaments. The two major forms are:

• Symphysis – fibrocartilaginous joint (e.g., intervertebral discs, pubic symphysis)
• Syndesmosis – bones joined by a ligament or interosseous membrane (e.g., distal tibiofibular joint)

Diagrammatic section of a symphysis

Diarthroses (Freely Movable Joints)

Diarthroses (also called synovial joints) represent the majority of joints in the body and allow a wide range of motion. Characteristic features include:

• Articular cartilage
• Synovial membrane
• Joint capsule
• Synovial fluid
• Optional structures like menisci and articular discs

Diagrammatic section of a diarthrodial joint

Diarthrodial joint with an articular disk

Types of Diarthroses (Synovial Joints)

Ginglymus (Hinge Joint)

Permits flexion and extension in one plane. Example: elbow joint, interphalangeal joints.

Trochoid (Pivot Joint)

Allows rotation around a longitudinal axis. Examples:

• Proximal radioulnar joint
• Atlantoaxial joint

Condyloid joint (Ellipsoidal Joint)

Allows movement in two planes (flexion, extension, adduction, abduction). Example: radiocarpal joint (wrist).

Saddle joint (Articulatio sellaris)

Opposing surfaces are concavo-convex, permitting biaxial movement. Example: carpometacarpal joint of the thumb.

Ball and socket joint (Enarthrosis)

Multiaxial joint allowing movement in all directions. Examples: hip joint, shoulder joint.

Gliding joint (Arthrodia)

Flat or slightly curved surfaces that allow limited gliding. Examples:

• Zygapophyseal joints (between vertebrae)
• Carpal bones (excluding capitate with lunate)

See also

• Joint
• Ligament
• Articulation (anatomy)
• Cartilage
• Synovial membrane

External links

• Anatomy photo:20:st-2002 at the SUNY Downstate Medical Center

Look up Joint in Wiktionary, the free dictionary.

Gray's Anatomy

• Gray's Anatomy Contents
• Gray's Anatomy Subject Index
• About Classic Gray's Anatomy
• Glossary of anatomy terms

Anatomy atlases (external)

[1] - Anatomy Atlases

Adapted from the Classic Grays Anatomy of the Human Body 1918 edition (public domain)