Final answer:
Pronation is the motion of turning the palm of the hand backward, mainly facilitated by the pronator teres, while supination returns the palm forward. The pronator teres muscle assists in forearm pronation and flexion at the elbow, working with other muscles for a complete range of motion.
Step-by-step explanation:
The concept of pronation relates to the forearm motion where the palm of the hand is turned from a palm-forward position to a palm-backward position. This action is facilitated by muscles such as the pronator teres and the pronator quadratus. In contrast, supination is the forearm motion that moves the palm from palm backward to palm forward, corresponding to the anatomical position, and this movement is assisted mainly by the supinator muscle.
The pronator teres is one of the anterior muscles of the forearm and it not only helps in pronation but also assists in flexion at the elbow. It is a key muscle for motions that require turning the hand to face posteriorly. The pronator teres works in conjunction with other muscles like the supinator and the extensors triceps brachii and anconeus for the full range of forearm movements, including flexion, extension, supination, and pronation.