Which joint type allows movement in one direction only?

The hinge joint specifically allows for movement in one direction, facilitating flexion and extension. This type of joint is characterized by its structure, which resembles the mechanism of a door hinge, allowing the adjoining bones to move back and forth similar to the way a door swings open and closed.

An example of a hinge joint in the human body is the knee or elbow, where the motion is primarily in one plane, either bending or straightening. This unidirectional movement is crucial for various physical activities, allowing for stability and control in actions such as walking, lifting, or performing push-ups.

By understanding the nature of hinge joints, it becomes clear why they are fundamental in biomechanical movements, providing a clear line of motion that enhances functional movement patterns in various physical contexts.