A plane joint (arthrodial joint, gliding joint, plane articulation) is a synovial joint which, under physiological conditions, allows only gliding movement.
Plane joints permit sliding or gliding movements in the plane of articular surfaces. The opposed surfaces of the bones are flat or almost flat, with movement limited by their tight joint capsules. Plane joints are numerous and are nearly always small, such as the acromioclavicular joint between the acromion of the scapula and the clavicle. Typically, they are found in the wrists, ankles & between the 2nd and 7th sternocostals, vertebral transverse and spinous processes.2