Abductor Pollicis Longus: Learn Your Muscles

Inside: Our thumbs give us an edge over other animals. If you value your thumbs and the ability to use them, learn about the abductor pollicis longus.

Opposable thumbs help define us as a species. They give us an advantage over other animals. Then, when you mess up your hand and your thumb stop working correctly, your whole world seems to crumble.

You can’t lift your kids. You can’t open doors with doorknobs. You can’t hold your wine glass. Life is a mess.

One of the muscles crucial to thumb health is the abductor pollicis longus. Here’s more about this gripping muscle and what you can do to keep it healthy.


abductor pollicis longus

Thanks to the University of Washington Radiology for the image.

According to the Flash Anatomy Muscles Flash Cards, the origin of the abductor pollicis longus is in two spots. One origin is about halfway on the ulnar side of the radius. This is on the bottom of the top arm bone when your thumb is pointing up. The other point of origin is on the back/outside of your ulna near the insertion points of the anconeus and interosseous membrane.

The abductor pollicis longus inserts on the radial side of the base of the first metacarpal. This is on the edge of your hand, right near where the bottom bone in your thumb meets your wrist.


As the name indicates, the abductor pollicis longus abducts. Specifically, it moves the carpometacarpal joint of the thumb (that bone in your hand just beneath your thumb) away from the middle finger. It also helps extend this same joint. So, it’s one of the muscles that allows you to lift your thumb up off of the table.

Common Dysfunction

If you are unable to move your thumb away from your fingers or if you have pain while performing this activity, your abductor pollicis longus might be dysfunctional. Pay particular attention to whether your pain or dysfunction comes from the thumb or the bone in your hand that is in line with the thumb. This will help you decide which muscle is causing your issues.

Restoring or Maintaining Health

Any time you think that you have injured or torn a muscle, you need to contact your doctor immediately. Your doctor can order all of the appropriate imaging, medicine, and therapy necessary for you to heal as quickly and thoroughly as possible.

However, if you want to keep the abductor pollicis longus healthy, I have some suggestions. For optimal muscle health, you want to both strengthen and stretch this muscle. To strengthen it, you should practice abducting and extending your thumb. Remember, this means that you’ll move the thumb straight away from the fingers and also practice lifting it off of a flat surface.

To stretch the abductor pollicis longus, you want to perform the exact opposite motions of your strengthening exercises. You should slide your thumb as close to your fingers as possible.

Also, practice flexing your thumb. Flexing the thumb is a little trickier to describe because of the increased mobility of the joint at the base of the thumb when you move this way. Try to bring your thumb across to your palm. This accomplishes both flexion and adduction.

Then, reach your thumb straight away down. Honestly, I never move my hand this way. However, this is technically the way the thumb should move if we’re trying to just do flexion. These exercises aren’t glamorous, but they’ll keep your thumbs healthy and strong.

More Information

For those who are more interested in technical terminology and smaller muscles, I recommend Flash Anatomy Muscles Flash Cards. Any time a client comes to me with pain, I use these flash cards.

Do you have any other suggestions for strengthening or stretching the abductor pollicis longus? Let us know in the comments below.

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About Sarah Stockett

Hi, I'm Sarah! I'm a certified Pilates and yoga instructor with a passion for pain relief. I believe you can use simple exercises to relieve your aches + pains. AND, I believe I can teach you how.