I have been playing bass/guitar for around 2 and a half years, and still my left hand (fretting hand) hurts while playing and i need help with hand positioning my hand and wrist have to go to a 90 degree angle in order to play. I tried raising and lowering my strap and i cant remove my thumb since it's out of habit and i understand that may be the cause of the pain. The pain is in the palm and in the soft muscle under my thumb. HELP ME END THIS PAIN AND SUFFERING!!!!
You're going to have to get out of what seems to be the habit of using your thumb to grip the neck too hard. This is a far too common an occurrence, and leads to your symptoms. It often ends in RSI., which as a guitar or bass player, you do not want!
There seems to be something that tells us to squeeze hard on the back of the neck, particularly when playing barre chords - I did for years - and really there's no need. In fact, I get my students to play barre chords without thumb contact. It's not difficult, but I wouldn't advocate playing that way, it's just that it proves to them that a minimum amount of squeeze does the job just as well as strangling the neck.
Give it a try, break the habit, which won't be easy, but will be worth it.
Not an expert, but I've had pain in that area at the base of my thumb before. I worked on a few things. I can't say for sure which if any of these helped, but I don't seem to get the problem any more. So, my random ideas:
- When my goal is to break old habits and get new ones, I usually do it gradually. I can't just stop learning the other new things I need to learn (and that would be no fun). So instead I keep working on those other new things using my existing technique, and at the same time I spend just a few minutes a day doing exercises to learn the new technique. I find that the new technique eventually starts showing up in my other playing too.
- As Tim suggests, I tried to grip the neck less tightly. As an exercise, try lifting your thumb off the back of the neck and playing a note, or a scale. Or as another exercise, play one note while gradually varying the pressure of your fretting finger, till you figure out what the absolute minimum pressure required is to make the note sound without buzzing. Then try playing a scale with that just that pressure.
- I worked on not stretching my left hand out more than necessary: so, even when using one finger per fret, I try to leave my hand in a more relaxed position most of the time, stretching my fingers all the way out only when I need to reach across all four frets, and otherwise letting my hand rotate a bit to reach.
- I experimented with the position of my thumb. Most teachers recommend planting your thumb in the middle of the back of the neck, about level with your fingers. But there's room to move it around without completely leaving that position. For example, sometimes I let my thumb slide towards the nut a little more if it feels better.
- Vary my left hand position: especially with very repetitive lines I have a tendency to keep my hand in one position. But if I remember to move it around some, it helps my left hand relax. I'll even go so far as to learn the same riff in a couple different positions (e.g., using open strings vs. not) and switch between those as I'm playing.
If the pain is in your thumb and palm then it is most likely that it's your thumb position/gripping that's causing it. If you have small hands it gives you all the more reason to make sure that only the pad of your thumb (the part that leaves a fingerprint) touches the back of the neck and that your hand is relaxed enough for you to swivel on the pad to reach higher notes. Think of it this way: if this pain continues, your boat as a bass player is starting to sink. You need to toss something overboard to keep afloat, and the heaviest item is your cherished old thumb grip. Act now before the seas get rougher.