This article is written by Toru Hoshino, a jazz bassist and instructor based in Japan who teaches online lessons to students worldwide. In this article, he offers a simple fix for pain at the base of the left thumb when fretting.
Pain at the base of your left thumb while fretting is a common issue for players just starting out. Here’s a fix worth trying.
Contents
Try Fretting Without Using Your Thumb at All
Try fretting without using your thumb at all, and play do-re-mi-fa-sol-la-ti-do starting from the 3rd fret of the 3rd string.
It’ll feel really awkward — but notice where the effort is concentrated while you’re fretting.
If you’re relying on the strength of your fingers alone rather than the strength of your whole arm to do the pressing, try shifting to using the strength of your entire arm instead. Doing this, you can usually manage to fret the notes even without your thumb.
Now, Bring the Thumb Back — Just “Resting” It
That said, playing with no thumb at all is awkward. So bring the thumb back in, but with the image of just “resting” it in place.
Think of it as “resting” the thumb against the neck, not “clamping” it.
This takes a lot of the load off your thumb.
It’ll feel clumsy and a little difficult at first, but you should be able to feel a real reduction in strain on your thumb. Try to keep this image in mind as a general habit during practice.
If the base of your thumb keeps hurting, it can develop into tendinitis. The author has actually dealt with this himself — there was a stretch where overworking with a bad form caught up with me. If something hurts, that’s usually a sign something’s off, and it may be worth reconsidering your form and how you’re using your body.
A subtle shift like “clamping” versus “resting” the thumb is genuinely hard to self-diagnose — having a teacher watch your hand directly is the fastest way to catch it before it becomes an injury.
Want Personalized Feedback on Your Playing?
This is exactly the kind of thing that’s hard to fix alone — and where having a teacher makes all the difference.
At Line on Bass, I offer an online lesson service where you send me a video of your playing, and I give you specific, detailed feedback — every single day if you want.
Students from around the world are using this to fix exactly these kinds of issues and steadily improve their jazz bass skills.