Out of all the forearm muscles, the palmaris longus is the most unique and mysterious. I say this because 20% of people don’t actually have a palmaris longus muscle. Instead, their palmaris brevis takes over and picks up the reigns of the missing palmaris longus when lifting objects and working out.
Let’s take a look at the function of this muscle and then get into the best exercises to stretch and strengthen it.
Don’t forget the other flexors:
- Flexor carpi radialis workout
- Flexor carpi ulnaris strengthening exercises
- Flexor digitorum profundus workouts
- Flexor digitorum superficialis stretch
- Flexor pollicis longus workout
Palmaris longus anatomy
The palmaris longus is a superficial forearm flexor that helps to flex your wrist. It’s the most superficial of all the forearm flexors, meaning that it sits very close to the skin and is thus very easy to see when you perform its anatomical functions.
This long muscle originates from the medial side of your elbow and inserts into the hand, hence why it has a dual function.
Besides flexing the hand/wrist, the palmaris longus tightens the fascia of the palmar aponeurosis in your hand.  This function is crucial to our everyday lives because it enables us to grip objects like the kettle, TV remote, and the little phone device that you’re most likely reading on right now.
Palmaris longus exercises
The ideal palmaris longus workout consists of 3 components: stretching, flexion, and gripping. Let’s explore each one in more detail so that you know exactly how to perform the exercises.
1. Palmaris longus stretch
Out of all the palmaris longus exercises, this one is the simplest because it requires zero equipment. It’s also very easy to master, so you can start enjoying the benefits right away.
- Stand up straight and place one arm out in front of you, palm facing down.
- Extend your wrist up so that your palm is now facing forward.
- Then bring your other arm across your body and apply a stretch to the first hand by gently pulling your fingers back.
- Hold the stretch for 10-20 seconds, and then do the other hand.
Of course, this particular stretch works other muscles besides the palmaris longus. But that’s actually a good thing because it would really suck to have to do a specific stretch for each of the countless lower arm muscles.
2. Wrist flexions
This exercise is commonly called a wrist curl. But for the purpose of understanding the function of the palmaris longus, which again, some people don't have  let’s call it a wrist flexion. It makes us sound smarter anyway.
- Grab a dumbbell (start very light) and place your forearm on a flat surface with your hand dangling off the edge.
- Bend your wrist and allow the dumbbell to descend toward the floor until you feel a nice stretch.
- Come straight back up by curling your hand toward the meat of your forearm.
- Squeeze the muscle and then repeat for 10-15 reps and 2-3 sets. Don't forget your other arm!
The most obvious place to do this exercise is on a weight bench at the gym. But providing that you have access to a dumbbell (or really, anything that serves as a dumbbell), you can also do this drill at home on a table or desk.
3. Hand grip squeezes
If you don't have access to a dumbbell and also don’t have a gym membership, then this movement is one of the best palmaris longus exercises that you can do for more strength. Not only does it work the muscle in question, but it also strengthens virtually all of the muscles in the forearm, wrist, and hand. Here’s how to do it:
- Grasp the hand gripper between the palm of your hand and your fingers.
- Squeeze it by pushing your fingers and palm together.
- Keep squeezing until the two ends of the gripper make contact.
- Release the gripper under control and repeat for 8-12 squeezes.
If using the gripper hurts your hands, then you can always wear a pair of gym gloves to make the exercise tolerable. Similarly, if keeping a firm hold on the gripper is an issue, then you can use some cheap chalk to keep things running smoothly.
Extensors need training too:
- Extensor carpi radialis brevis workout
- Extensor carpi radialis longus workout
- Extensor carpi ulnaris exercise
- Extensor digitorum stretch
- Extensor pollicis brevis drills
Should you train them with weights?
The question that springs to mind with most small muscles like the palmaris longus is this: Do I need to do special exercises for it?
Unless you’re having trouble with it, my answer is no. Regular resistance training strengthens the forearms quite nicely.
Plus, if you do need to strengthen your palmaris longus, it’s not like you can even isolate it; you’re going to be working loads of other forearm muscles too.
So while you can certainly do direct forearm and grip training, there’s no need to devise an exercise for every little muscle that resides in your lower arms. Otherwise, you'll be quite literally living in the gym.
What are the most effective palmaris longus muscle exercises?
As long as you’re stretching and strengthening the muscle, then any exercise will suffice. I personally like to begin with some kind of wrist flexion or grip exercise and then finish with a stretch to relieve any tension that might have built up in the muscle over the course of the workout.
In terms of the palmaris longus exercises that I just showed you, I most recommend the grip squeezes because they train wrist flexion and your grip simultaneously, which helps you to gain functional strength rather than just pure muscle mass.
- Vasković, J. (2020, October 29). Palmaris longus muscle. Kenhub. https://www.kenhub.com/en/library/anatomy/palmaris-longus-muscle
- Soltani, A. M., Peric, M., Francis, C. S., Nguyen, T.-T. J., Chan, L. S., Ghiassi, A., Stevanovic, M. V., & Wong, A. K. (2012). The Variation in the Absence of the Palmaris Longus in a Multiethnic Population of the United States: An Epidemiological Study. Plastic Surgery International, 2012, 1–4. https://doi.org/10.1155/2012/282959