Audio LecturePro Feature Extensor Carpi Ulnaris 0:00 / 0:00 1x 0.25x 0.5x 0.75x 1x 1.25x 1.5x 1.75x 2x The extensor carpi ulnaris is a muscle within the superficial compartment of the posterior forearm. Its medial position within the forearm produces adduction as well as extension at the wrist. The tendon of the extensor carpi ulnaris passes through the 6th extensor compartment at the wrist. Attachments: Originates from the lateral epicondyle of the humerus, and posterior border of the ulna. It attaches to the base of fifth metacarpal. Actions: Extension and adduction of wrist. Innervation: Radial nerve (deep branch). Blood supply: Ulnar artery By TeachMeSeries Ltd (2026) Fig 1The muscles in the superficial layer of the posterior forearm. 3D ModelPro Feature 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 Dissection AtlasPro Feature Prosection of the superficial layer of muscles within the posterior compartment of the forearm. Prosection of the superficial layer of muscles within the posterior compartment of the 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 In gratitude to our body donorsLearn more In gratitude to our body donors We are deeply grateful to the individuals who chose to donate their bodies for the advancement of medical education. Their generosity makes these images possible and provides students and healthcare professionals with an invaluable opportunity to study human anatomy. We recognise the profound contribution made by each donor and their families, and we use these images with the dignity and respect their gift deserves. Acknowledge Frequent questions What is the function of the extensor carpi ulnaris muscle? The extensor carpi ulnaris muscle primarily facilitates wrist extension and adduction. Its positioning in the forearm allows it to effectively contribute to these movements during various activities. Where does the extensor carpi ulnaris originate and insert? This muscle originates from the lateral epicondyle of the humerus and the posterior border of the ulna. It inserts at the base of the fifth metacarpal, enabling its functional role in wrist movement. Which nerve innervates the extensor carpi ulnaris? The extensor carpi ulnaris is innervated by the deep branch of the radial nerve. This innervation is crucial for the muscle's ability to perform its actions effectively. What is the blood supply to the extensor carpi ulnaris? The blood supply to the extensor carpi ulnaris is provided by the ulnar artery. This vascular support is essential for maintaining the muscle's function and health. How does the position of the extensor carpi ulnaris affect its action at the wrist? Due to its medial position in the forearm, the extensor carpi ulnaris aids in both adduction and extension of the wrist. This anatomical arrangement allows for coordinated wrist movements during various tasks. Rate This Article