Supinator - Podcast Version 0:00 / 0:00 1x 0.25x 0.5x 0.75x 1x 1.25x 1.5x 1.75x 2x The supinator is a muscle within the deep compartment of the posterior forearm. It forms the floor of the cubital fossa, and has two heads – which the deep branch of the radial nerve passes between. Attachments: Originates from the lateral epicondyle of the humerus and the posterior surface of the ulna. Inserts onto the posterior surface of the radius. Actions: Supination of the forearm. Innervation: Radial nerve (deep branch). Blood supply: Ulnar artery. By TeachMeSeries Ltd (2026) Fig 1Muscles in the deep layer of the posterior forearm. Pro Feature - 3D Model You've Discovered a Pro Feature Access our 3D Model Library Explore, cut, dissect, annotate and manipulate our 3D models to visualise anatomy in a dynamic, interactive way. Learn More Pro Feature - Dissection Atlas Prosection of the radial nerve in the forearm. It divides into superficial and deep branches within the proximal forearm. Prosection of the radial nerve in the forearm. It divides into superficial and deep branches within the proximal forearm. You've Discovered a Pro Feature Access our Dissection Image Library Enhance your understanding with high-resolution dissection images showcasing real-life anatomy. Learn More Frequent questions What is the supinator muscle? The supinator is a muscle located in the deep compartment of the posterior forearm that facilitates the supination of the forearm. It plays a crucial role in rotating the forearm to turn the palm upwards. Where does the supinator muscle originate and insert? The supinator muscle originates from the lateral epicondyle of the humerus and the posterior surface of the ulna, and it inserts onto the posterior surface of the radius. This anatomical arrangement allows it to effectively perform its function. What nerve innervates the supinator muscle? The supinator muscle is innervated by the deep branch of the radial nerve. This nerve passes between the two heads of the muscle, highlighting its importance in motor function. What is the primary action of the supinator muscle? The primary action of the supinator muscle is the supination of the forearm. This action is essential for various daily activities that require the rotation of the forearm. What is the blood supply for the supinator muscle? The blood supply to the supinator muscle is provided by the ulnar artery. This vascularisation is vital for maintaining the muscle's function and health. Rate This Article