The supinator, pronator teres, and pronator quadratus all act to ______ the forearm.Multiple choice question.extendflexrotate

To answer the question, let's analyze the functions of the muscles mentioned:

1. Supinator: This muscle is primarily responsible for supinating the forearm, which means it rotates the forearm so that the palm of the hand faces upward or forward.

2. Pronator Teres: This muscle's main function is to pronate the forearm. Pronation refers to the rotation of the forearm such that the palm faces downward or backward.

3. Pronator Quadratus: Like the pronator teres, the pronator quadratus is also involved in the pronation of the forearm.

Analysis

Considering the actions of each muscle:

• The supinator acts to supinate (rotate outward).
• The pronator teres and pronator quadratus act to pronate (rotate inward).

Conclusion

Given that the question asks for a collective action involving the supinator, pronator teres, and pronator quadratus, we focus on what two of these muscles are primarily doing, which is pronation.

Final Answer

The supinator, pronator teres, and pronator quadratus all act to rotate the forearm, specifically pronating it.