Pronator Quadratus

Authors

Affiliations

Nate Yomogida, B.S., SPT

Doctor of Physical Therapy

B.S. in Kinesiology

Chloë Kerstein, B.S., SPT

Doctor of Physical Therapy

B.A. in Neuroscience

Figure 1: Muscles that move the Forearm¹

Reading list

• Wrist and finger flexor Muscles²
• ³

Muscle	Origin	Insertion	Innervation	Action
Pronator quadratus	Distal 1/4 of anterior Ulna	Distal 1/4 of anterior Radius	Median n. C8 - T1	Elbow/Forearm: Pronation Distal RUJ: Stabilization

Origin

The PQ’s proximal origin is at the anterior surface of the distal 1/4 of ulna^4,5 and on an aponeurosis that partially covers the muscle⁵.

Insertion

The PQ courses from its common origin and separates into superficial and deep fibers⁵. The superficial fibers project laterally and insert onto the distal 1/4th of radius (anterior surface)^4,5.

The deeper fibers project laterally from the common origin and insert superior to the radius’ ulnar notch⁵.

Innervation

Anterior Interosseous N. (C8, T1)⁴

Action

• Forearm: Pronation⁴, specifically at the proximal radioulnar joint⁵.
  • During this action, the radial head pivots around the ulna⁵.
• Distal RUJ: Stabilization⁴ by holding the distal radius and ulna together⁵.
  • This stabilization and protective function also protects the interosseous membrane⁵.

The PQ “unwinds” ulna around the radius⁵.

Notes

1.

Betts JG, Blaker W. Anatomy and Physiology. 2nd ed. OpenStax; 2022. https://openstax.org/details/books/anatomy-and-physiology-2e/?Book%20details

2.

Donnelly JM, Simons DG, eds. Travell, Simons & Simons’ Myofascial Pain and Dysfunction: The Trigger Point Manual. Third edition. Wolters Kluwer Health; 2019.

3.

Neumann DA, Kelly ER, Kiefer CL, Martens K, Grosz CM. Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation. 3rd ed. Elsevier; 2017.

4.

Gilroy AM, MacPherson BR, Wikenheiser JC, Voll MM, Wesker K, Schünke M, eds. Atlas of Anatomy. 4th ed. Thieme; 2020.

5.

Jones B. B Project Foundations. b Project; 2025.