Absolutely Everything You Need to Know About Flexor Digitorum Profundus

Inside: If throwing a good punch or opening a jar of pickles is important to you, you’ll want to learn about the flexor digitorum profundus muscle.

Often, we don’t appreciate our hand muscles until there’s something wrong and we can’t do what we’re used to doing. These small muscles survive with relatively little attention–right up until we can’t open the stinking jar of pickles! Then, we start paying attention and try to figure out what’s gone wrong.

If you’re having trouble opening your pickle jar or you’ve discovered that your hand won’t make a nice, tight fist when you go to hit your brother, you may have issues with your flexor digitorum profundus muscle. Here’s more about this important hand muscle and what you can do to keep it healthy.


flexor digitorum profundus muscle

Thanks to the University of Washington Radiology for the image.

The flexor digitorum profundus muscle originates on about three-fourths of the anterior and medial surfaces of the ulna. It also originates on the interosseous membrane and the deep fascia of the forearm.

When you move into anatomical neutral with your palms rotated forward (which doesn’t feel very neutral for many people), you can easily feel the point of origin for this muscle. Press on the front of your forearm just a little bit below your elbow. Slide around the side of your upper forearm to the part that’s closest to your body. These are points of origin for the flexor digitorum profundus muscle.

This muscle inserts via four tendons to each of your four fingers. Each tendon inserts on the very top of each finger, a spot known as the base of the distal phalanx. Before this muscle inserts on each finger, it passes through the tendon of the flexor digitorum superficialis.


The flexor digitorum profundus muscle flexes the fingers, bones in  the hand beneath the fingers, and the wrist joint. In other words, when you curl your fingers into a fist, you’re using the flexor digitorum profundus. Then, when you bend your wrist, as you might do when removing the lid from a jar of pickles, you are also using this muscle.

Common Dysfunction

If you are unable to curl your fingers or wrists, or if you have pain when you do, you might have a dysfunctional flexor digitorum profundus muscle. This inability to comfortably curl the fingers and bend the wrist would result in the inability to grip things (like pickle jars). Lid removal would be more difficult, as would making a fist to punch your brother.

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 flexor digitorum profundus muscle healthy, I have some suggestions. For optimal muscle health, you want to both strengthen and stretch this muscle. To strengthen this muscle, practice flexing your fingers and wrists. Make fists and open pickle jars to keep this muscle strong.

Then, to stretch it, extend your fingers and wrists. Practice Plank pose or just press your hands flat on the table. Use your other hand to carefully stretch your fingers backward.

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 flexor digitorum profundus muscles? 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.