Final answer:
A movement that decreases the angle of a joint, bringing the bones closer together, is known as flexion. It's an angular movement that's opposed by extension, which increases the joint angle. Understanding these movements is vital in many health and science-related fields.
Step-by-step explanation:
Flexion is a type of angular movement in which the angle between bones at a joint is reduced, effectively bringing the adjacent bones closer together. It's commonly observed in the sagittal plane, for example, when moving the forearm upward at the elbow or curling the fingers towards the palm. This action is opposed by extension, which increases the angle between the bones, effectively straightening the joint. In the context of the spine, flexion involves anterior bending of the vertebral column. Joints capable of this movement, such as the synovial joints, allow the body a great range of motion, necessary for countless activities.
The opposite of flexion is extension, where the angle between bones of a joint increases. There are also special movements that include actions such as elevation, depression, and rotation, which are not categorized solely as angular movements. Understanding these movements is crucial in fields such as medicine, physical therapy, and sports sciences, as they are integral to the body's biomechanics.