Flexion

noun
  1. The action of bending or the condition of being bent, especially the bending of a limb or joint. noun
    The flexion of the elbow is necessary to bring the hand to the mouth.
    During the physical examination, the doctor checked the flexion of the patient's knee.
  2. A movement that decreases the angle between two body parts, typically referring to the bending of a joint. noun
    Flexion of the fingers is required to make a fist.
    In yoga, flexion of the spine can help improve posture and flexibility.