Which classification of joints is NOT a type of freely movable joint?

Synarthrosis refers to a type of joint that is immovable. This classification is characterized by the absence of a joint cavity, with bones typically being connected by fibrous tissue or cartilage. As such, synarthroses serve to provide stability and support rather than mobility. Freely movable joints, known as diarthroses, include hinge joints, ball and socket joints, and pivot joints, which all allow for significant movement in various planes. Each of these types of freely movable joints facilitates different ranges of motion, such as flexion and extension in hinge joints, multidirectional movement in ball and socket joints, and rotational movement in pivot joints. The key distinction here lies in the degree of mobility, highlighting that synarthrosis does not allow for movement, making it the correct answer in this context.