I play with my left thumb (fretting hand) to the left of the index finger. It is the most relaxed position to me.
I have seen it recommended in videos and on here many times that it should not be to the left of the index finger, but rather, it should be placed behind the middle finger, or possibly in between the index and middle fingers.
Whenever I try to put my thumb anywhere but to the left of the index finger, my left hand can cramp up and it’s not comfortable. Every teacher I have ever been to was adamant that it had to be behind my middle finger, despite expressing my discomfort.
I personally believe you should play comfortably above all else, but I am really curious what other people’s preference is, and where they place their thumb.
Thanks.
Obviously your teacher is not a guitar player. Just to clarify, we are talking about electric bass, not a double bass that requires techniques I can’t fathom.
I just spent the last 20 minutes playing the bass watching where my thumb is placed. My honest observation is my thumb is not in the same spot relative to the fingers as I move up and down the fingerboard. That said, 99% of the time my thumb is left of my index or even with index finger. It is rare when my thumb is even with my middle finger, and never past it.
Further after 55 years of playing bass, I’ve developed an arthritic condition at the basel thumb joint. Like you, trying to keep my thumb under my middle finger made me most uncomfortable.
i know I don’t have the best technique in the world, but I have zero problems getting notes out of my bass, up and down the finger board. In fairness to your instructor, I’m not sure what she is trying to accomplish. Seems to me this technique would really slow you down once you are “out of the box”.
IMO, the thumb should be more like a pivot point as opposed to an anchor, and allow for you to rock your hand back and forth. I will say this that my left hand from the tip of my thumb to the tip of my pinky when my hand stretched out flat is about 9.5” which might allow me to get away with some things a little different.
if you have just started with this instructor, I’d give it a couple of more weeks with daily practice session (20 minutes minimum) between lessons using this technique. If you are still experiencing discomfort (not fatigue), discuss it with the instructor. If the advice is to stay the course, I’d find somebody else.