Abduction is any motion of the limbs or other body parts that pulls away from the midline of the body. Swinging the hands from the side of the body up to the shoulder or higher is abduction. For fingers and toes, abduction spreads the digits away from the hand or foot’s centerline of hand or foot.
Plantar flexion refers to the flexion or extension of the foot at the ankle. It is the movement that decreases the angle between the back of the leg and the sole of the foot. An example of plantar flexion is a ballerina extending her foot in line with her leg.
Flexion refers to a movement that decreases the angle between two body parts. Flexion at the elbow is decreasing the angle between the ulna and the humerus. When the knee flexes, the ankle moves closer to the buttock, and the angle between the femur and tibia gets smaller.
Definition of inversion, a movement. The term inversion may used to describe movement at a joint e.g. how two body parts move in relation to each other. This or related words may also be used to describe the action of certain muscles that cause such movement.
Short definition of Protraction (in the context of a term to describe movement of the body): Protraction is movement of a body part in the anterior direction, i.e. being drawn forwards. The movement of protraction is the opposite of the movement of retraction.
Rotation is movement in which something, e.g. a bone or a whole limb, pivots or revolves around a single long axis. It is useful to know other words related to "rotation", including: rotator - a muscle that can act to cause an rotation movement at a joint is called an rotator. For example, the abductor pollicis longus muscle.