carpometacarpal joint

anatomy

Also known as: carpometacarpus

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Last updated

June 24, 2026

Quick Summary

The carpometacarpal joint is a type of sellar joint found in the thumb. This joint allows for two primary movements: flexion-extension and abduction-adduction. Additionally, it permits combined movements that include rotation, enabling the thumb to swing and oppose the fingers. This oppositional movement is crucial for grasping and manipulation, and is considered fundamental to human civilization.1

The carpometacarpal joint is formed by the articulation of the carpal bones of the wrist with the metacarpal bones of the hand. The carpal bones are arranged in two rows, with the distal row firmly attached to the metacarpals. The metacarpals themselves form arches in the hand, accommodating muscles, tendons, and nerves, and allowing for the bringing together of the fingertips and thumb for manipulation.23

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bird
Skeleton
…toward the body) of the carpometacarpus. When the elbow joint is flexed (bent), the radius slides forward on the ulna and pushes the radiale against the carpometacarpus, which in turn flexes the wrist. Thus the two joints operate simultaneously. The U-shaped ulnare articulates with the ulna and the carpometacarpus. Anatomists…
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…toward the body) of the carpometacarpus. When the elbow joint is flexed (bent), the radius slides forward on the ulna and pushes the radiale against the carpometacarpus, which in turn flexes the wrist. Thus the two joints operate simultaneously. The U-shaped ulnare articulates with the ulna and the carpometacarpus. Anatomists…
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hand
…apes it rotates at the carpometacarpal joint, and it is therefore opposable to the other fingers and may be used in combination with them to pick up small objects.
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…apes it rotates at the carpometacarpal joint, and it is therefore opposable to the other fingers and may be used in combination with them to pick up small objects.
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joint
Sellar joint
…a sellar joint is the carpometacarpal joint of the thumb. The thumb can be swung from side to side or from behind forward, but the most frequent movement is that in which the thumb swings so that it comes “face to face” with one or another of the fingers, as…
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…a sellar joint is the carpometacarpal joint of the thumb. The thumb can be swung from side to side or from behind forward, but the most frequent movement is that in which the thumb swings so that it comes “face to face” with one or another of the fingers, as…
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