So I would suggest getting control of the thumb before it gets control of you and you can't undo it.
Of course everyone's anatomy is different and it might never hinder you in any way. You might be putting your thumb under the strings as a way to not stretch or find a shortcut that might not be good.
I remember when I first started playing piano, and I would stick my fingers towards the wall or harp of the upright piano while pushing keys down. It was sort of an unconscious muscle movement like we all do when we learn something new. Think of how you might stick your tongue out when you use scissors or color. Haha. My teacher would say, "stop pointing at the guy across the street."
I used to know a guitar player that never learned good wrist technique, so he just wailed away with his forearm to get louder or more intense. Imagine your arm was in a cast and you tried to play guitar. It caused problems for him, but because he learned that way...the rest is history.
Unlearning is sometimes harder than learning.
Of course everyone's anatomy is different and it might never hinder you in any way. You might be putting your thumb under the strings as a way to not stretch or find a shortcut that might not be good.
I remember when I first started playing piano, and I would stick my fingers towards the wall or harp of the upright piano while pushing keys down. It was sort of an unconscious muscle movement like we all do when we learn something new. Think of how you might stick your tongue out when you use scissors or color. Haha. My teacher would say, "stop pointing at the guy across the street."
I used to know a guitar player that never learned good wrist technique, so he just wailed away with his forearm to get louder or more intense. Imagine your arm was in a cast and you tried to play guitar. It caused problems for him, but because he learned that way...the rest is history.
Unlearning is sometimes harder than learning.