There are six different kinds of synovial joints in the human body.
Synovial joints are the most common and movable type of joint in the body. They are characterized by the presence of a fluid-filled joint cavity. These joints allow for a wide range of movements and are classified based on the shape of the articulating surfaces and the types of movements they permit.
Here's a breakdown of the six types of synovial joints:
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Hinge Joint: Allows movement in one plane (uniaxial), like the elbow or knee. Think of a door hinge. It permits flexion and extension.
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Pivot Joint: Allows rotational movement (uniaxial), such as the atlantoaxial joint between the first and second cervical vertebrae (allowing you to shake your head "no").
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Saddle Joint: Allows movement in two planes (biaxial), permitting flexion, extension, abduction, adduction, and circumduction. The carpometacarpal joint at the base of the thumb is a prime example.
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Plane (or Gliding) Joint: Allows gliding or sliding movements (nonaxial or multiaxial), such as those between the carpal bones of the wrist or the tarsal bones of the ankle.
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Condyloid (or Ellipsoidal) Joint: Allows movement in two planes (biaxial), permitting flexion, extension, abduction, adduction, and circumduction. Examples include the metacarpophalangeal joints (knuckles).
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Ball and Socket Joint: Allows movement in multiple planes (multiaxial), offering the greatest range of motion, including flexion, extension, abduction, adduction, rotation, and circumduction. The hip and shoulder joints are examples.
In summary, while all synovial joints share a common structure, they differ in their shape and the types of movements they allow, resulting in six distinct classifications.
