Definition

1. Noun:
   • A type of synovial joint: A rotatory joint is a freely moving joint (a diarthrosis) where the primary, and often only, possible movement is a rotation around a central axis. This axis is typically a single, fixed point or a peg-like process of one bone fitting into a ring or notch of another.

Usage

• The term is a technical, anatomical term. It is synonymous with the more commonly used term pivot joint in anatomical and medical contexts.
• It is used to describe the specific biomechanical function and structure of certain joints in the body.

Examples

• Noun:
  • The atlantoaxial joint, connecting the first two vertebrae, is a classic example of a rotatory joint, allowing the head to turn from side to side.
  • In the forearm, the proximal radioulnar articulation is a rotatory joint that enables the rotation of the palm (pronation and supination).

Advanced Usage

• Functional Classification: In anatomy, joints are classified by their function (the degree of movement they allow). A is a type of uniaxial joint, meaning it permits movement around only one axis.
• Structural Classification: Structurally, it is a type of synovial joint, characterized by a joint cavity filled with synovial fluid.

Variants and Related Words

• Pivot Joint (n): The standard, more frequently used synonym for in anatomical nomenclature.
• Trochoid Joint (n): An alternative, less common technical term for the same joint structure.
• Rotation (n): The primary movement allowed by a rotatory joint.
• Uniaxial Joint (n): The functional category to which rotatory/pivot joints belong.

Synonyms

• Pivot joint
• Trochoid joint

Antonyms

• Immovable joint (synarthrosis): A joint permitting little or no movement, like the sutures of the skull.
• Multiaxial joint: A joint allowing movement around multiple axes, such as a ball-and-socket joint (e.g., the hip).

Noun

1. a freely moving joint in which movement is limited to rotation
   • the articulation of the radius and ulna in the arm is a pivot joint