What movements characterize flexion and extension?

The correct description of flexion and extension is that flexion refers to bending a joint, which decreases the angle between two body parts, while extension refers to straightening a joint, which increases the angle between those body parts. This concept is foundational in understanding human movement and biomechanics.

For example, when you bend your elbow to bring your forearm closer to your upper arm, you are performing flexion. Conversely, when you straighten your elbow, moving the forearm away from the upper arm, you are performing extension.

Understanding this distinction is crucial for fitness professionals, as it influences how exercises are prescribed and performed. Recognizing these movements allows trainers to effectively design programs that enhance flexibility, strength, and overall joint function.