Describe the joints and movements involved in turning a doorknob

When you turn a doorknob, there are two movements involved in the elbow:

pronation: is the movement of the hands to turn the palms posteriorly. That is, it involves placing the palms into the prone (face-down) position, like  looking at the backs of the hands. supination : is the movement with the arms extended to the sides of the trunk and palms facing forward. Another way of thinking about supination is how someone would move their hands to look at their palms or to hold a bowl of soup.

Radiohumeral joint is formed by the articulation of radius and humerus. The radius is specially designed to rotate at the elbow

Is there a passage that comes with this question or should i know this right off the bat, because if it is, i probably have short term memory loss or college is too stressful