Muscle
Pronator quadratus
Short pronator near the wrist
High-yield
Unlike pronator teres, it acts near the wrist and is supplied by the anterior interosseous nerve. Its role includes forearm rotation and support of the distal radioulnar joint.
Overview
This deep muscle bridges the front of the distal ulna and radius. Its transverse pull rotates the radius for pronation, while deeper fibers contribute to the relationship between the two distal forearm bones.
Reference facts
- Origin
- Anterior surface of the distal quarter of the ulna
- Insertion
- Anterior surface of the distal quarter of the radius
- Action
- Pronates the forearm and contributes to distal radioulnar stability
- Innervation
- Anterior interosseous branch of the median nerve; commonly C8-T1
- Blood supply
- Anterior interosseous arterial branches
Clinical correlation
The muscle lies over the front of the distal radius and is encountered during surgery there. Its close relationship to the anterior interosseous nerve and wrist capsule matters when planning an approach.
Frequently asked questions
What does the pronator quadratus do?
The pronator quadratus pronates the forearm and contributes to distal radioulnar stability.
What nerve innervates the pronator quadratus?
Anterior interosseous branch of the median nerve; commonly C8-T1.
Where does the pronator quadratus attach?
Origin: Anterior surface of the distal quarter of the ulna. Insertion: Anterior surface of the distal quarter of the radius.
What is the blood supply of the pronator quadratus?
Anterior interosseous arterial branches.