Which movement decreases the joint angle?

The movement that decreases the joint angle is flexion. This type of movement involves bringing two body parts closer together, which effectively reduces the angle between them. For example, when you bend your elbow to bring your hand towards your shoulder, you are performing elbow flexion, thereby decreasing the angle at the elbow joint.

In contrast, when considering the other movements:

• Extension increases the angle between body parts, like straightening a bent elbow.

• Abduction involves moving a limb away from the midline of the body, which does not decrease an angle.

• Circumduction is a circular movement that typically combines flexion, extension, abduction, and adduction, resulting in a full rotation at the joint, rather than focusing on decreasing an angle.

Thus, flexion specifically refers to the action of decreasing the angle at a joint, making it the correct answer.