Audio LecturePro Feature Abductor Pollicis Longus 0:00 / 0:00 1x 0.25x 0.5x 0.75x 1x 1.25x 1.5x 1.75x 2x The abductor pollicis longus is a muscle within the deep compartment of the posterior forearm. The tendon of the abductor pollicis longus passes through the 1st extensor compartment at the wrist, where it contributes to the radial border of the anatomical snuffbox. Attachments: Originates from the interosseous membrane and the adjacent posterior surfaces of the radius and ulna. It attaches to the lateral aspect of the base of the first metacarpal. Actions: Abduction of the thumb. Innervation: Radial nerve (posterior interosseous branch). Blood supply: Ulnar artery. By TeachMeSeries Ltd (2026) Fig 1Muscles in the deep 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 Borders and contents of the anatomical snuffbox Borders and contents of the anatomical snuffbox 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 abductor pollicis longus? The abductor pollicis longus is a muscle located in the deep compartment of the posterior forearm. It plays a crucial role in the abduction of the thumb. Where does the abductor pollicis longus originate? This muscle originates from the interosseous membrane and the posterior surfaces of the radius and ulna. These attachments provide the necessary leverage for its function. What is the primary action of the abductor pollicis longus? The primary action of the abductor pollicis longus is to abduct the thumb. This movement is essential for grasping and pinching actions. Which nerve innervates the abductor pollicis longus? The abductor pollicis longus is innervated by the radial nerve, specifically its posterior interosseous branch. This innervation is vital for muscle contraction and thumb movement. What is the blood supply to the abductor pollicis longus? The blood supply to the abductor pollicis longus comes from the ulnar artery. Adequate blood flow is important for muscle health and function. Rate This Article