Abduction is the term used to refer to the motion of moving a limb away from the Sagittal plane, as seen on the left. The Sagittal plane is sometimes referred to as the “median plane” as well.
Abduction is the opposite motion of adduction, which is the motion of moving a limb towards the center of the Sagittal plane.
Exercises include shoulder, wrist, finger, thumb, hip, and toe abduction. All stretching the muscles by moving the limb or appendage away from the Sagittal plane.

Two very common exercises using abduction can be seen on the sides here. Hip abduction and shoulder abduction are used to work the Gluteus medius muscle and Deltoid muscle respectively.
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