The pronator quadratus is a small, square muscle in the forearm, part of the deep flexors. It is the deepest forearm muscle, located beneath the flexor digitorum superficialis. Originating from the ulna, it attaches to the radius, facilitating pronation by rotating the radius medially. The median nerve, specifically its branch, innervates this muscle. The pronator quadratus is crucial for forearm pronation, distinguishing it from other deep flexors responsible for hand and finger flexion.

Which muscle is the deepest in the forearm?

• Brachioradialis

• Flexor digitorum superficialis

• Extensor carpi radialis

• Pronator quadratus

Where does the pronator quadratus muscle originate?

• Distal end of the radius

• Distal end of the ulna

• Proximal end of the radius

• Proximal end of the ulna

Which nerve is responsible for the innervation of the pronator quadratus muscle?

• Radial nerve

• Musculocutaneous nerve

• Ulnar nerve

• Median nerve

What is the primary function of the pronator quadratus muscle?

• Extension of the fingers

• Pronation of the forearm

• Flexion of the wrist

• Supination of the forearm

Why is the pronator quadratus muscle named as such?

• It is a triangular muscle that causes supination.

• It is a long muscle that causes extension.

• It is a square muscle that causes pronation.

• It is a round muscle that causes flexion.