Pronator teres
Supinator. Also, as pronator teres also contributes to flexion of the elbow, that action is antagonized by the triceps.
In your forearm. Your pronators are located on the anterior surface of your arm, while the supinator is located on the posterior surface. The brachioradialis is another pronator and supinator, which is also in your forearm, and is located on top of the radius. The bicep brachii is another supinator, on the upper half of your arm ( above the elbow)
The antagonist muscles of the elbow joint are the biceps brachii and brachialis, which oppose the action of the triceps brachii. In the radioulnar joint, the supinator and biceps brachii act as antagonists to the pronator teres and pronator quadratus muscles.
The shoulder muscle that is considered the strongest supinator is the biceps brachii.
The biceps brachii muscle acts as a synergist for supination of the hand. It works in coordination with other muscles, such as the supinator muscle, to rotate the forearm and bring the palm facing upwards.
This is mostly achieved by the Pronator Teres and hte Pronator Qudratus muscles.
The relationship between pronator quadratus and supinator muscles can be described as antagonistic. Pronator quadratus pronates the forearm (rotates it inward), while the supinator supinates the forearm (rotates it outward), producing opposite actions at the radioulnar joint.
supinator
The biceps brachii is the strongest supinator of the body. It is a powerful muscle located in the upper arm that helps to rotate the forearm into a palm-up position.
pronator teres and supinator
supinator muscle hold your arm like u r holding a bowl of soup, hand facing up. pronators pour out the soup, hand facing down.
The supinator muscle, bicipital aponeurosis and brachioradialis muscle