What is the term for the action that occurs when the angle of a joint decreases?

The action that occurs when the angle of a joint decreases is referred to as flexion. This movement typically brings two body parts closer together, effectively reducing the angle between them. For example, when you bend your elbow, the angle between the forearm and the upper arm decreases, demonstrating flexion at the elbow joint.

Flexion is an essential concept in understanding human movement, as it is involved in various activities such as walking, running, and lifting. Recognizing flexion is crucial for anyone studying anatomy or physical fitness, as it helps in designing effective exercise programs that target specific muscle groups.

The other terms, such as extension, retraction, and rotation, describe different types of movements. While extension increases the angle at a joint, retraction pertains to moving a structure backward along a horizontal plane, and rotation involves turning a part of the body around an axis. Understanding these distinctions allows for a better grasp of biomechanics and movement patterns in fitness and rehabilitation settings.