Origin
Radius, ulna.
Insertion
1st metacarpal.
Blood supply
Posterior interosseous artery.
Nerve supply
Posterior interosseous nerve.
Action
It controls some movements of the thumb like extension, side-to-side movement and rotation of the thumb. It also helps to extend and flex the wrist joint. You use this muscle to grip, grasp, and hold the things like holding a pen or a glass of water.
Disease/Injury
Overuse of muscle in gripping and grasping the things and trauma leads to pain and swelling of the thumb. The muscle is also involved in carpal tunnel syndrome.
Muscle Exercise
To make your thumb strong, make a tight clenched fist, put your thumb on the outside of your various other fingers. Hold this tension for 10 seconds, relax for 10 seconds and then repeat.
Interesting Facts
You use the muscle to nod the thumb, to make an act of thumbs up.
