ANATOMY

Detailed explanation-1: -Carpal-metacarpal joint of the thumb is an example of saddle joint . It is a type of synovial joint, wherein the opposing surfaces are reciprocally-concave and convex.

Detailed explanation-2: -Synovial: Saddle A saddle joint is an articulation between two bones that are saddle-shaped, or concave in one direction and convex in another. This type of joint is biaxial, and one example is the first carpometacarpal joint between the trapezium (carpal) and the first metacarpal bone of the thumb.

Detailed explanation-3: -The thumb basal joint, also called the carpometacarpal (CMC) joint, is a specialized saddle-shaped joint that is formed by a small bone of the wrist (trapezium) and the first bone of the thumb (metacarpal).

Detailed explanation-4: -Saddle Joint Saddle joints are functionally classified as biaxial joints. The primary example is the first carpometacarpal joint, between the trapezium (a carpal bone) and the first metacarpal bone at the base of the thumb.

Detailed explanation-5: -Synovial joints are often further classified by the type of movements they permit. There are six such classifications: hinge (elbow), saddle (carpometacarpal joint), planar (acromioclavicular joint), pivot (atlantoaxial joint), condyloid (metacarpophalangeal joint), and ball and socket (hip joint).