Supinator Muscle

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: Left Humerus (Anterior view)¹

Figure 2: Muscles that move the Forearm²

Reading list

• Supinator Muscle³
• Neumann⁴
• MMT⁵

Muscle	Origin	Insertion	Innervation	Action
Supinator	Olecranon Lateral epicondyle Radial collateral lig. Annular lig.	Radius (between radial tuberosity and pronator teres)	Radial n. C6 - C7	Radioulnar joints: Supination

Origin

The supinator muscle has a common proximal origin before separating into deep and superficial layers:⁶

• Lateral epicondyle of Humerus^6,7.
• Ulnar attachment is either the Olecranon of Ulna⁷ or supinator crest adjacent to the ulnar fossa⁶.
• Radial collateral ligament^6,7.
• Annular ligament of radius^6,7.

Insertion

The supinator wraps around the proximal 1/3rd of the of the radius and it inserts on the proximal, lateral, posterior radial surface⁶.

According to gilroy⁷, the supinator muscle inserts onto the Radius (between radial tuberosity and insertion of pronator teres)⁷

Pathway

• Consists of both superficial and deep layers⁶.

• Radial surface of supinator is bordered by: ECRB & ECRL muscles⁶

• The ulnar side of the supinator is covered by the inferior part of the anconeus

Innervation

Posterior Interosseous N. (C6, C7)⁷

Action

Forearm: Supination

Synergists: Strong and forceful supnation requires assistance from the Biceps brachii, thus the most powerful supination occurs when the elbow is at 90° flexion to maximize biceps brachii efficiency⁶.

Antagonists

• Pronator quadratus⁶

Notes

1.

Gray H. Anatomy of the Human Body. 20th ed. (Lewis WH, ed.). Lea & Febiger; 1918. https://www.bartleby.com/107/

2.

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

3.

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

4.

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

5.

Weinstock D. NeuroKinetic Therapy: An Innovative Approach to Manual Muscle Testing. North Atlantic Books; 2010.

6.

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

7.

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