Saddle joint
Saddle joints are a type of synovial joint that allow articulation by reciprocal reception. Both bones have concave-convex articular surfaces which interlock like two saddles opposed to one another.
Movements
Saddle joints allow movement with two degrees of freedom much like condyloid joints. They allow flexion / extension, abduction / adduction and therefore also allow circumduction. Unlike ball and socket joints, saddle joints do not allow axial rotation.
- flexion / extension
- abduction / adduction
- cirumduction
Examples
- first carpometacarpal joint between the trapezium and the first metacarpal of the thumb
- sternoclavicular joint