The pronator quadratus muscle is located in the anterior compartment of the forearm, forming part of the deep muscles in the region. It is a relatively small and square-shaped muscle that occupies the space between the ulna and radius.

Origin:
Originating from the distal portion of the anterior surface of the ulna, the pronator quadratus takes its starting point from the bony structure of the forearm.

Insertion:
The muscle inserts into the distal portion of the anterior surface of the radius. This insertion site establishes a connection with the forearm bone.

Function:
Functionally, the pronator quadratus is a powerful pronator of the forearm. It plays a key role in rotating the radius over the ulna, turning the palm downward or facing backward. Additionally, the muscle assists in maintaining stability between the ulna and radius during movements involving forearm rotation. The pronator quadratus is particularly active in activities such as turning a doorknob, using a screwdriver, or any movement that involves rotating the forearm. It contributes to the complex movements and functional range of motion in the lower arm.

Pronation