Pronator quadratus (Musculus pronator quadratus)
Educational content only — not medical advice.
Anatomy
A flat quadrangular muscle bridging the distal radius and ulna just above the wrist — the primary pronator and the main stabiliser of the distal radioulnar joint.
Origin & insertion
Distal quarter of the anterior ulnar surface and its border.
Action
Pronates the forearm and compresses the two bones together, resisting diastasis in distal forearm fractures.
Innervation
Median nerve — anterior interosseous branch (C8–T1).
Clinical notes
Galeazzi fracture (ulnar shaft with distal dislocation) disables its pull and destabilises the radius; restoring the joint is essential for function.
Related structures
Educational references
FAQ
What is the role of the Pronator quadratus?
A flat quadrangular muscle bridging the distal radius and ulna just above the wrist — the primary pronator and the main stabiliser of the distal radioulnar joint.
Why is the Pronator quadratus clinically important?
Galeazzi fracture (ulnar shaft with distal dislocation) disables its pull and destabilises the radius; restoring the joint is essential for function.
Source & license
BodyParts3D, © The Database Center for Life Science licensed under CC Attribution 4.0 International (https://creativecommons.org/licenses/by/4.0/). license details