Plane joint

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Synovial joints are the main type of joints found in the body.

Plane joints, also known as gliding joints, are one of the six types of synovial joints, the others being hinge, pivot, ellipsoid, saddle, and ball-and-socket. They are formed by the articulation between two relatively flat articular surfaces of opposing bones and permit sliding/translation movements in the same plane of the articular surfaces. These joints are typically small and the movement within most plane joints is fairly limited by tight joint capsules. 

Some examples of synovial plane joints include the acromioclavicular, costovertebral, interchondral, second to seventh sternocostal, intermetatarsal, and some intercarpal joints.

The functional description of plane joints varies between different textbooks and resources. They are most widely accepted as being non-axial, as gliding movements do not involve rotation about an axis. However, some resources describe them as uni-axial, presumably as gliding movements are still one type of movement, whilst others describe them as multi-axial, as gliding in many directions within a plane is possible.