What type of joint is classified as freely movable?

The classification of joints as synarthrosis, amphiarthrosis, or diarthrosis is based on the degree of movement allowed. A diarthrosis joint is characterized by its high mobility, allowing for a wide range of movements in various directions. This is exemplified by joints such as the shoulder, hip, and knee, which facilitate intricate movements like rotation, flexion, and extension.

In contrast, synarthrosis joints are immovable and are typically found in structures where stability is more important than mobility, such as the sutures in the skull. Amphiarthrosis joints provide limited movement and are generally found in areas like the spine, where some flexibility is necessary, yet rigid stability is also needed.

Therefore, categorizing a joint as diarthrosis signifies its role in enabling significant movement, which is essential for many functions within the human body.