Whenever I hear The Boss’s song, Glory Days, I immediately start picturing my athlete yogis in my mind (perhaps not the most common reaction to a song, but it’s mine). Among them, there is a common thread: they all want to continue playing and keep the Glory Day reflections at bay.

While many traditional coaches focus on the bigger picture of the body, smaller yet extremely important muscles may be overlooked. The flexor digitorum superficialis, an extrinsic flexor muscle at the proximal interphalangeal joints of the second through fifth fingers is one of those. Wait – what does that mean? Take a moment to reflect how many movements you do where your fingers or wrist are flexing and extending in a given day. It’s a lot! Your flexor digitorum superficialis is the MVP in that movement.

Take care of your flexor digitorum superficialis to maintain your motor skills.

Why focus on this? Tending to the flexor digitorum superficialis allows a baseball player to grasp the baseball before pitching or throwing it. It allows an equestrian to have a softer, more refined tune on the reins. It allows a receiver to catch a football and tuck it in for safe keeping while sprinting to the touchdown line. A hockey player has greater control of his stick and puck by contracting and releasing the flexor digitorum superficialis in the slightest increments. It even allows me to type this article. Bend/extend/bend/extend as my fingers strike the keyboard.

OK, so where do I find it? The flexor digitorum superficialis is located on the anterior side of the forearm and originates at the bottom edge of the upper arm bone, or more specifically the medial epicondyle of the humerus, and at the ulna and radius. As it tracks down the forearm, it fissures into 4 channels through the carpel tunnel and ultimately attaching to the sides of the second knuckle of your 2nd through 5th fingers.

So, moral of the story, don’t be sidelined and let your Glory Days pass you by because your flexor digitorum superficialis didn’t get enough love. Remember – it’s the MVP, gold medalist, shining star in its movement. Don’t let the big guys overshadow it.

“I had a friend was a big baseball player
back in high school
He could throw that speedball by you
Make you look like a fool boy
Saw him the other night at this roadside bar
I was walking in, he was walking out
We went back inside sat down had a few drinks
But all he kept talking about was
Glory days 
they’ll pass you by
Glory days”

Bruce Springsteen

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Lindsay Smith

Lindsay Smith, E-RYT 500, is a certified Yoga Tune Up® instructor and graduate of YogaWorks 500-Hour Yoga Teacher Training who specializes in teaching yoga to professional and Olympic athletes. Lindsay’s unique approach to yoga infuses sport-specific poses, anatomical awareness, and invigorating breath work. She has coached some of the best athletes in their fields from the high school, collegiate, professional, and Olympic levels. Working directly with coaching staff, Lindsay’s approach to yoga provides every athlete the opportunity to maximize their performance in their position, and longevity in their sport. Although athletes are Lindsay's specialty she also works with individuals of all ages and abilities using her skills and unique point of view to customize an appropriate set of postures to surpass your goals.

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Love this. I was tasked with creating a rolling exercise for the forearms and arms and this was a great factoid to throw in there and so very true – and I love Bruce Springsteen so any reference thereof resonates! I am constantly fascinated by the complexity of movement our bodies are capable of. Thank you.


Thank you for pointing out the value of the flexor digitorum superficialis, and how crucial it is to both sports and everyday hand usage.

Jennifer Mayer

I’m working on this for a roll class. I type all day, but now I have so many more examples to bring to my students. I might start by serenading the class with some classic BOSS! Thanks for your suggestions!

Jessica Haims

Lindsay thank you for the insight on how our little muscles play major roles. I am guilty of forgetting to take care of the “little man” from time to time, but we use these “little guys” so much that it’s important to keep them strong but mobile. Thank you for the reminder that big movements, although great and important, still need the assistance of “forgotten” muscles such as the flexor digitorum superficialis. I’m going to get back to my drills such as big toe little toe to work on some “smaller” muscles groups!


Oh that’s awesome!
Now I know a little more about the arms for my YTU training presentation!
Flexor digitorum superficialis here we go!

Catherine Jervis

Great article! In crossfit, we use these muscles ALL THE TIME for gripping the rig, barbell, kettlebell– you name it! It’s so important to have strong and healthy flexor digitorum superficialis. This article was great to explain behind the scenes what’s happening with that muscle.

Thu Maraia

I also, use the ball to do the “Plow” onto that side of my forearm, and it helps with tighness from weitght lifting, doing bicep curls, and also carrying groceries with the bags dangling on my forearm.


I was searching on the blog for posts related to the forearm. After coming across your article, I have a much clearer picture of this muscle. Thanks!!
By the way, I happened to notice a typo in the 3rd paragraph of the word ‘humerus’, just thought you’d want to know.

Julie Thomas


Love the context of the article. I always appreciate to learn more about the forearm and wrist. You are right they are so overlooked. Just about anybody could benefit from giving this MVP some love. I myself have been using the yoga tune up balls up and down to find some relief. I am looking forward for a Wrist,hand, forearm Immersion coming From Jill Miller in the future.


The forearm muscles are those things we don’t realize how much we use them! It’s one of those situations where we don’t recognize how important they are until something is injured or goes wrong with them unfortunately. I love using my YTU balls on my forearms!

Sophie D

I appreciate your lightheartedness, now I can only smile and picture you singing this song out loud and your stretch, strengthen or roll your forearm. As a massage therapist, I have to be aware to prevent build-up of tension in my forearms because I want a long career but mostly, I want to continue rock climbing, skiing and mountain biking forever without limitations in my wrists. Thanks for the precision and humour.


Great explanation of this forearm muscle. I’ve been typing quite a bit lately and have been craving the stretch you mention in your other article. I must be over working the flexor digitorum superficialis. I’ll be adding the recommended roll out on the YTU therapy balls as well. Thank you!


Thanks for your post, Lindsay. You made the complex relationship between the forearm and hand a lot clearer for me. Considering the action of the flexor digitorum superficialis, I suspect that hand gripping exercises would be more beneficial if the hand strengthening regimen also included rolling our the forearms with YTU therapy balls.

Yvonne Duke

Thank you for this blog Lindsey. Timing is everything. I am currently on a mini golf vacation and just read your blog. I must be gripping my club a little too tight because my flexor digitorum superficilas on my right arm was a tad tight afterwards. I will be “rolling out” before golf tomorrow.


Love your work Lindsay 🙂