What type of joint is found at the knee?

The knee joint is classified as a hinge joint, which is specifically designed to allow movement primarily in one direction. This type of joint permits flexion and extension, resembling the action of a door hinge. The knee facilitates bending (flexion) and straightening (extension), making it crucial for activities such as walking, running, and jumping.

In contrast, a ball and socket joint allows a greater range of motion, including rotation, as seen in the hip or shoulder joint. A pivot joint allows one bone to rotate around another, like the joint in the neck that allows for head rotation. A saddle joint provides a unique shape that permits greater mobility than a hinge joint, but not as much as a ball and socket joint, found in areas like the thumb. Understanding these distinctions highlights why the knee's structure and movement capabilities classify it as a hinge joint.