Flexion refers to the action of bending a joint, resulting in a decrease in the angle between the bones involved in the joint. This movement typically occurs in the sagittal plane, which divides the body into left and right halves. Flexion is a common movement in various joints, such as the elbow, knee, and shoulder. For example, when you bend your elbow to bring your hand closer to your shoulder, that is flexion of the elbow joint.
In addition to flexion, there is also extension, which is the opposite movement, involving the straightening of the joint and increasing the angle between the bones. Flexion and extension are fundamental movements involved in activities like walking, running, and lifting.
These movements help to increase the efficiency of body functions and enable the body to perform a wide range of motions necessary for daily activities and athletic performance.