Final answer:
Motions in the frontal plane include abduction and adduction, which are movements of the limbs toward and away from the midline of the body.
Step-by-step explanation:
Motions in the frontal plane include abduction and adduction, which occur around an anterior-posterior axis. Abduction is the movement of a limb or digits away from the midline of the body, such as lifting the arms laterally at the shoulders. Adduction is the opposite movement, bringing the limbs or digits toward the body's midline, like lowering the arms to the sides. These motions are present at various synovial joints, including the shoulder, hip, and fingers.