Left Hand Thumb With Cello
When I started cello back in 2013, details were skipped over in lessons. I am not going to get into my instructor issues again, or my stopping and starting with lessons. Unfortunately, the skipping over details of right and left hand use has created bad habits, which are hard to break, and could be physically damaging. I am going to talk a little about that left hand thumb.
Apparently, I have been using it wrong. Unfortunately, the the wrong way now feels comfortable and right. It is extremely hard to change.
I used to just put the left thumb behind the neck. I did not curve it. I did not worry about whether it was stiff or loose. I just had it holding the cello, most often, tightly. Yikes! I just heard a lot of cellist run there bows diagonally across their strings making horrid scratchy sounds! That was from cellists who know how wrong what I was doing was. So sorry!
My new instructor is really trying to correct my bad habits. I am the proverbial old dog trying to learn new tricks. It is not easy. This bad habit will not only cause me issues playing my cello, it can cause issues with my thumb physically due to stress. The fact that my grip is also strong just adds to the issue being detrimental to my left thumb wellness. It is like I think that cello is going to get onto its endpin and hop away and I have to keep it from escaping.
I need to loosen my grip, curve my thumb and move it with my hand and stop reaching my fingers forward while leaving my thumb in one static place. I am working on it, and am getting more and more aware of my thumb each time I play. I find that sometimes I notice it when I am doing pretty good intonation wise and I adjust my thumb and/or hold, and out the window goes all that intonation accuracy. I have to start again with that section with my thumb correct.
It is important to correct your thumb as soon as you notice it has gone back to your old ways. You want the proper way to use it to be the natural comfortable way. The thumb is not supposed to be holding the cello. The cello will stay in place without your thumb. The thumb assists in your fingering. Your fingers move up and down and left and right, and your thumb needs to follow that motion. Since there are differing beliefs as to which finger your thumb is opposing on the underside of the neck, I will not mention which finger. You must not grip the cello with the thumb, though. Another bad habit!
Now I have to work on a curved relaxed thumb, keeping the thumb across the proper finger (there are exceptions), and allowing my thumb to follow my fingers up and down and left and right as I play, not keep it static. My thumb has always been perpendicular to the neck and that joint was pressing on the neck, really stressing the thumb jointS. It does not just affect that top joint. This puts a lot of stress on that top joint, but also the base joints, down to the wrist. This is not good. Tendonitis could result, and other issues. You can look it up for more details, I am not a doctor. Just trying to make cello students aware that misuse of the left thumb can cause playing issues, AND physical damage to your thumb. Don’t thumb your nose to proper left thumb use on a cello.
Disclaimer #1: I am just a student. Do what your instructor says. If you notice pain or stress in your left thumb, ask your instructor to check your left thumb use as you are playing and make corrections, if necessary. I would request (s)he continue checking it and paying attention to it until the proper hold is natural for you. If I were you, I would also see a doctor.
Disclaimer #2: I am still a student. My explanations may not be exact 100%. Also, your instructor may differ. Use your own judgement. This is strictly FYI, and my experience.