A type of synovial joint called a joint consists of articulating surfaces that are nearly flat and are slightly curved.

The type of synovial joint you're referring to is a plane joint (also known as a gliding joint). In plane joints, the articulating surfaces are usually flat or slightly curved, allowing for limited movement in various directions, typically sliding or gliding movements. These joints are characterized by their ability to permit motion along multiple axes, but the range of motion is generally small compared to other types of synovial joints, such as hinge or ball-and-socket joints.

Examples of plane joints in the human body include the intercarpal joints in the wrist and the intertarsal joints in the ankle. The slight curvature of the articulating surfaces helps to facilitate smooth movements while also allowing for some degree of flexibility and adaptability. The joint capsule in these joints is often thin. Overall, plane joints play an essential role in the fine motor movements required for dexterity and coordination in various activities.