what do extension and flexion mean
When a joint can move forward and backward, such as the neck and trunk, flexion refers to movement in the anterior direction. Flexion of the shoulder or hip refers to movement of the arm or leg forward. Extension is the opposite of flexion, describing a straightening movement that increases the angle between body parts.When a joint can move forward and backward, such as the neck and trunk, extension refers to movement in the posterior direction.For example, when standing up, the knees are extended.ee also: List of flexors of the human body and List of extensors of the human body. Flexion and extension describe movements that affect the angle between two parts of the body. These terms come from the Latin words with the same meaning.