What type of joint allows for movement in one direction, such as the elbow?

The hinge joint is specifically designed to allow movement primarily in one plane, facilitating motions that resemble the opening and closing of a door. This type of joint permits flexion and extension, which is precisely the type of movement seen at the elbow. In the elbow joint, the articulation between the humerus and the ulna allows the forearm to bend and straighten while restricting motion in other directions, making it an ideal example of a hinge joint's functionality.

In contrast, ball-and-socket joints allow for more complex movement, including rotation, found in joints like the shoulder and hip. Pivot joints enable rotational movement around a single axis, as seen in the neck where the atlas and axis vertebrae allow for head rotation. Gliding joints allow for sliding movements between flat surfaces, which occurs between the bones in the wrists and ankles. Thus, the unique structure and functional characteristics of hinge joints make them suitable for one-directional movement, exemplified by the elbow.