Synovial Joint
Synovial Joints: Synovial joints are the most common joint type in the human body. They have a unique structure that includes a joint capsule, synovial fluid, articular cartilage covering bone surfaces, articular discs, intricate ligament systems to support motion, and often bursae. This unique structure allows for more motion than fibrous joints (also known as immovable joints) and cartilaginous joints (partly moveable joints).
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All Synovial Joint Types:
Synovial Joint Brief Summary:
- Hinge Joint: A hinge joint (also called a ginglymus joint) is a synovial joint in which the articular surfaces fit one another in a way that is analogous to the hinge of a door. Generally, these joints permit motion in one plane. Examples include the elbow, the knee (unless considered a condyloid joint), and the interphalangeal joints.
- Ball and Socket Joint: A ball and socket joint (also called a spheroid joint or spheroidal joint) is a synovial joint in which the rounded or spherical end of one bone fits into a cup-like depression of another bone. The distal bone is capable of motion around an indefinite number of axes, which have one common center. Examples of ball and socket joints include the hip and shoulder (glenohumeral) joints.
- Pivot Joint: A pivot joint (also called a trochoid joint, rotary joint, or lateral ginglymus joint) is a type of synovial joint in which the cylinder of one bone fits into a corresponding cavity, allowing for rotational motion. Examples include the articulation between the first and second cervical vertebrae (c1/c2 a.k.a. atlas/axis) and the proximal radioulnar joint.
- Gliding Joint: A gliding joint (also called an arthrodial joint, plane joint, or plane articulation) is a synovial joint that allows only gliding movement in the plane of the articular surfaces. The opposed surfaces of the bones are flat or almost flat, with movement generally limited by tight capsules and ligaments. Gliding joints are numerous, are most often small, and allow very little motion. Examples include the carpal joints of the wrist, the tarsal joints of the ankle, and the facet joints of the spine.
- Saddle Joint: In a saddle joint (also called a sellar joint or articulation by reciprocal reception), the opposing surfaces are reciprocally concave-convex, allowing for motion in 2 planes. Motion is similar to how a horseback rider can move in a saddle. Examples include the trapeziometacarpal (TMC) joint of the thumb (1st carpometacarpal joint) and the sternoclavicular (SC) joint.
- Condyloid Joint: A condyloid joint (also called condylar, bicondylar, ellipsoid, or ellipsoidal) is an ovoid articular surface, or condyle, that is received into an elliptical cavity. These joints permit movement in two planes. Examples include the knee, metacarpophalangeal joints, and metatarsophalangeal joints.