Pronator Quadratus
Musculus pronator quadratus
Pronator quadratus is a small, deep square muscle spanning the distal radius and ulna that initiates pronation and stabilizes the distal radioulnar joint against the forces of gripping. It works with pronator teres during any palm-down rotation under load and helps hold the two forearm bones together during heavy carries and presses. It is rarely trained in isolation but is essential to forearm rotational integrity.
- Actions
- Forearm pronation, Holds the radius and ulna together at the distal radioulnar joint
- Origin
- Anterior surface of the distal ulna
- Insertion
- Anterior surface of the distal radius
- Innervation
- Anterior interosseous branch of the median nerve (C7-C8, T1)
- Blood supply
- Anterior interosseous artery
Synergists Pronator Teres
Antagonists SupinatorBiceps Brachii