Abductor Pollicis Longus Muscle Overview – Human Anatomy | Kenhub

Abductor Pollicis Longus Muscle Overview – Human Anatomy | Kenhub


Hello there once again! It’s Matt from Kenhub,
and in this tutorial, we will be discussing the abductor pollicis longus. The deep extensors
of the forearm consist of five muscles located at the posterior side of the forearm. One
of them, the abductor pollicis longus, an extrinsic muscle of the hand, is going to
be the focus of this tutorial. The muscle bellies and tendons of this group of muscles
form the surface of the distal forearm and the wrist where they can be easily palpated. The abductor pollicis longus muscle originates
at the dorsal surfaces of both the radius and ulna and the interosseus membrane. This
muscle also lies just below the supinator muscle. The abductor pollicis longus has its
insertion at the base of the first metacarpal bone, the metacarpal bone of the thumb. Often,
the insertion tendons splits into two and, additionally, attaches to the trapezium. Like all extensors of the forearm, these five
muscles are innervated by the radial nerve. The radial nerve divides into a superficial
branch and deep branch at the height of the radial head. The deep branch becomes the posterior
interosseus nerve which is responsible for the innervation of almost all deep extensors. The main function of the deep extensors is
to move the joints of the hand and fingers. The abductor pollicis longus pulls the thumb
forward at the saddle joint resulting in abduction which leads to a lateral movement of the radius
at the wrist joint at the same time known as radial deviation. This muscle also functions
to carry out dorsiflexion of the metacarpal joint of the thumb. This video is more fun than reading a textbook,
right? If you want more videos, interactive quizzes, articles, and an atlas of human anatomy,
click on the “Take me to Kenhub” button. It is time to say goodbye to your old textbooks
and say hello to your new anatomy learning partner, Kenhub! See you there! https://www.kenhub.com

5 Replies to “Abductor Pollicis Longus Muscle Overview – Human Anatomy | Kenhub”

  1. Informative video. are there movements or workouts that would make this muscle bigger ? I'm just asking because if I'm correct about the muscle I'm talking about. The one on my left wrist seems way harder and bigger then the one on my right.

  2. I have pronator teres syndrome, and my abductor pollis BREVIS has been unused for years because it has wasted away. Thanks to the abductor pollis longus, I can abduct my thumb and do other tricks, although it doesn't do as good a job by itself. My thumb muscles that still receive nerve input have grown very large to make up for my median nerve failure. I am currently in physical therapy, and I hope the decompression of my median nerve will allow my thumb muscles to function normally someday. I'd say I've adapted quite nicely.

  3. Hi everyone! Hope you enjoyed watching our video on the abductor pollicis longus muscle. Please let us know what you would like us to cover on the next videos. Are you ready to further your knowledge? Check out our article on the deep extensors of the forearm here: https://khub.me/umigj. Enjoy! 🙂

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