Flexion is a type of movement that decreases the angle between two body parts. It typically occurs at joints, such as the elbow or knee, allowing limbs to bend. For example, when you lift your arm to wave, your elbow flexes, bringing your forearm closer to your upper arm. This movement is essential in many daily activities, such as walking, running, and lifting objects. Flexion is often paired with its opposite movement, called extension, which increases the angle between body parts. Understanding flexion helps in fields like physiotherapy and sports science, where joint movement is crucial for performance and rehabilitation.