Although the forearm muscles are one of the smallest muscle groups of the human body, they actually have so many individual muscles that it can be hard to remember them all.
However, the importance of strengthening muscles like the extensor pollicis brevis cannot be understated. This particular muscle is very important for your grip because it extends the thumb, so we need to keep it active without overstressing it if we want to develop lower arm and hand strength for our everyday activities.
See our other extensor guides:
- How to stretch your extensor carpi radialis brevis
- Exercises for the extensor carpi radialis longus
- Extensor carpi ulnaris exercises
- Extensor digitorum exercise
Extensor pollicis brevis insertion, origin, and function
The extensor pollicis brevis muscle is located in the posterior compartment of the forearm. It inserts into the radius, and because it’s a fairly long muscle, it extends right into the thumb. 
Unlike some of the other forearm muscles that we’ve discussed, the extensor pollicis brevis is actually a deep extensor of the forearm rather than a superficial one. This means that it lies further away from the skin than the other muscles.
Therefore, we need more than simple wrist extensions to train this commonly overlooked muscle. We use our thumbs in everyday life to grip a variety of different objects, so you definitely don’t want to skip these exercises and stretches.
Extensor pollicis brevis exercises and stretches
1. Thumb extensions
The great thing about this exercise is that it requires minimal equipment. And you most certainly don’t have to go to a gym to do it. In fact, all you need is a rubber band and a table.
Grip one end a rubber band with one hand and then hook the other side of the band around your opposite hand. Then, with the hand that’s hooked in the band, extend your thumb upwards by pushing against the band.
You’ll want to slowly lower the band back down to the starting position so that your extensor pollicis brevis can enjoy the full resistance.
2. Thumb extension with abduction
Once regular thumb extensions become easy, you can add some slight abduction to further engage your extensor pollicis brevis and the surrounding muscles. 
Like before, you want to hook one thumb around the rubber band and grab the other end of the band with your opposite hand. From there, you want to extend your thumb upwards. But, as you reach full extension, you also want to move your thumb out to the side (abduction) to increase the intensity of the exercise.
I like this version better because the thumb tends to extend and abduct simultaneously during everyday activities—It doesn’t simply move straight up and down.
3. Bodyweight extensions
Again, this exercise is strikingly similar to the first two drills. However, this one is more for the beginner crowd because you’re just using your bodyweight. Well, the weight of your thumb.
You simply place your fist on the table in a neutral hand position (not pronated or supinated) and then slowly extend your thumb upwards.
Concentrate on your form. And then, once you’ve got the technique down, you can incorporate some abduction into the movement since, as we just established, the thumb doesn’t just move straight up and down since we're not robots.
How important is training the extensor pollicis brevis?
Considering that most forearm, wrist, and hand drills don’t sufficiently work the extensor pollicis brevis, it’s very important to isolate this muscle via thumb extensions if you’re having problems with it.
Of course, the great thing is that, unlike for brachioradialis workouts, you don’t need any special equipment to get the full set of benefits. A simple rubber band and a flat surface are the only requirements to do extensions for your extensor pollicis brevis.
- Anconeus exercise
- Flexor carpi radialis stretch
- Flexor carpi ulnaris tendonitis exercises
- Flexor digitorum profundus exercises
- Flexor digitorum superficialis stretches exercises
- Flexor pollicis longus exercises
- Palmaris longus muscle exercises
- Pronator quadratus muscles exercise
- Pronator teres exercises
There are many different variations of extensor pollicis brevis exercises and stretches. However, as you’ll soon learn, most simply have you hold the band a bit differently or place your hand in slightly varied positions.
For example, if for some reason you don’t have access to a flat surface to do thumb extensions the way that I recommended, then you can hook one end of the band around your thumb and the other end around your fingers (of the same hand) and extend your thumb upwards.
In other words, your fingers act as the flat surface. So you can do this exercise for your extensor pollicis brevis pretty much anywhere.
- Grujičić, R. (2020b, October 29). Extensor pollicis brevis muscle. Kenhub. https://www.kenhub.com/en/library/anatomy/extensor-pollicis-brevis-muscle
- Extensor Pollicis Brevis. (n.d.). Physiopedia. https://www.physio-pedia.com/Extensor_Pollicis_Brevis