What is the term used when the joint angle increases?

The term used when the joint angle increases is "extension." This movement occurs when the angle between two body segments increases, allowing them to move away from each other. For example, extending the arm straightens the elbow joint, increasing the angle between the forearm and the upper arm.

In the context of joint movements, flexion refers to the decreasing of the joint angle, such as bending the elbow or knee. Adduction and abduction describe movements toward or away from the body's midline, respectively. While adduction moves a limb closer to the center of the body, abduction moves it away. Therefore, extension specifically denotes the action of increasing the joint angle, which is crucial in understanding joint movements and anatomy.