Final answer:
Supination and pronation are movements of the forearm. Supination refers to the palm facing forward, while pronation refers to the palm facing backward.
Step-by-step explanation:
Supination and pronation are movements of the forearm. In the anatomical position, the upper limb is held next to the body with the palm facing forward. This is the supinated position of the forearm. In this position, the radius and ulna are parallel to each other.
When the palm of the hand faces backward, the forearm is in the pronated position, and the radius and ulna form an X-shape.