AFAA Personal Trainer Certification Practice Exam

What movement is characterized by decreasing the angle at a joint?

1. Extension

2. Flexion

3. Abduction

4. Adduction

The correct answer is: Flexion

The movement that is characterized by decreasing the angle at a joint is known as flexion. This action typically occurs in hinge joints, such as the elbows and knees, and is essential in many daily activities, like bending the arm or knee. When flexion occurs, the two segments of the limb or body part come closer together, effectively reducing the angle between them. This is particularly noticeable when considering movement patterns like lifting something off the ground by bending at the knees or pulling the forearm towards the shoulder, which are both clear examples of flexion in action. In contrast, extension is the opposite movement, where the angle at a joint increases, creating a straightening motion. Abduction refers to moving a limb away from the midline of the body, while adduction involves moving a limb closer to the body's midline. Both of these movements do not primarily focus on the angle between bones at a joint in the same way that flexion does.