The Abductor Pollicis Longus is a muscle located in the forearm. It plays a crucial role in the movement of the thumb, specifically in the abduction and extension of the thumb at the carpometacarpal joint. This muscle originates from the posterior surfaces of the radius and ulna bones and the interosseous membrane. This muscle is innervated by the radial nerve, which is responsible for controlling movements in the arm and hand. The Abductor Pollicis Longus is essential for various hand functions, including grasping and pinching, making it important for daily activities and fine motor skills.